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University of California • Berkeley

Regional Oral History Office University of California

The Bancroft Library Berkeley, California

Program in the History of the Biosciences and Biotechnology

Paul Berg, Ph.D.

A STANFORD PROFESSOR'S CAREER IN BIOCHEMISTRY, SCIENCE POLITICS,
AND THE BIOTECHNOLOGY INDUSTRY

With Introductions by
Daniel E. Koshland, Jr., Ph.D.

and
Charles Yanofsky, Ph.D.

Interviews Conducted by

Sally Smith Hughes, Ph.D.

in 1997

Since 1954 the Regional Oral History Office has been interviewing leading
participants in or well-placed witnesses to major events in the development of
northern California, the West, and the nation. Oral history is a method of
collecting historical information through tape-recorded interviews between a
narrator with firsthand knowledge of historically significant events and a well-
informed interviewer, with the goal of preserving substantive additions to the
historical record. The tape recording is transcribed, lightly edited for
continuity and clarity, and reviewed by the interviewee. The corrected
manuscript is indexed, bound with photographs and illustrative materials, and
placed in The Bancroft Library at the University of California, Berkeley, and in
other research collections for scholarly use. Because it is primary material,
oral history is not intended to present the final, verified, or complete
narrative of events. It is a spoken account, offered by the interviewee in
response to questioning, and as such it is reflective, partisan, deeply involved,
and irreplaceable.

************************************

All uses of this manuscript are covered by a legal agreement
between The Regents of the University of California and Paul Berg
dated November 18, 1997. The manuscript is thereby made available
for research purposes. All literary rights in the manuscript,
including the right to publish, are reserved to The Bancroft Library
of the University of California, Berkeley. No part of the
manuscript may be quoted for publication without the written
permission of the Director of The Bancroft Library of the University
of California, Berkeley.

Requests for permission to quote for publication should be
addressed to the Regional Oral History Office, 486 Bancroft Library,
Mail Code 6000, University of California, Berkeley 94720-6000, and
should include identification of the specific passages to be quoted,
anticipated use of the passages, and identification of the user.
The legal agreement with Paul Berg requires that he be notified of
the request and allowed thirty days in which to respond.

It is recommended that this oral history be cited as follows:

Paul Berg, Ph.D., "A Stanford Professor's
Career in Biochemistry, Science Politics,
and the Biotechnology Industry," an oral
history conducted in 1997 by Sally Smith
Hughes, Regional Oral History Office, The
Bancroft Library, University of
California, Berkeley, 2000.

Copy no.

Paul Berg, 1980.

Cataloguing information

BERG, Paul (b. 1926) Professor of biochemistry

A Stanford Professor's Career in Biochemistry, Science Politics, and the
Biotechnology Industry, 2000, xiv, 249 pp.

Childhood and education, New York City; higher education, New York,
Pennsylvania State University, Washington University, St. Louis;
postdoctoral research with Arthur Kornberg and Herman Kalckar; research on
amino acid activation, tumor viruses, recombinant DNA; Asilomar I
conference (1973), recombinant DNA biohazards controversy, Asilomar
Conference on Recombinant DNA Molecules (1975); commercialization of
recombinant DNA & molecular biology; Nobel Prize, 1980; DNAX Research
Institute of Molecular & Cellular Biology, Inc., relations with Schering-
Plough; Beckman Center for Molecular & Genetic Medicine, Stanford Medical
School; Stanley N. Cohen, Herbert W. Boyer, Peter Lobban, James D. Watson,
John Morrow, Joshua Lederberg, and other scientists.

Introductions by Daniel E. Koshland, Jr., Professor of Molecular and
Cell Biology, UC Berkeley, and Charles Yanofsky, Professor of
Biological Science, Stanford University.

Interviewed 1997 by Sally Smith Hughes for the Program in the History
of the Biological Sciences and Biotechnology, Regional Oral History
Office, The Bancroft Library, University of California, Berkeley.

TABLE OF CONTENTS--Paul Berg

BIOTECH SERIES HISTORY by Sally Smith Hughes i

INTRODUCTION by Daniel E. Koshland, Jr. v

INTRODUCTION by Charles Yanofsky vi

INTERVIEW HISTORY by Sally Smith Hughes x

BIOGRAPHICAL INFORMATION xiv

I CHILDHOOD AND EDUCATION 1
Family and Early Education 1
Abraham Lincoln High School 4
Sophie Wolf 5

II COLLEGE, GRADUATE, AND POSTGRADUATE STUDENT 8
Chemical Engineering Student at City College of New York 8
Biology Student at the Brooklyn College Campus 9
Biochemistry Student at Pennsylvania State University, 1943- 1948 10
Military Service in World War II 11
Return to Penn State 13

Marriage 13

Decision to Do Graduate Work in Biochemistry 13

Graduate Student, Western Reserve University, 1948-1952 14

Applying to Graduate Schools 14

Decision to Attend Western Reserve 16

The Department of Clinical Biochemistry 16

Research on the Artificial Kidney 17

Joining the Department of Biochemistry 17

Research on Nutritional Supplements 19

Berg's Initial Research Project 20

Countering du Vigneaud 22

Harland Wood and Radioisotopic Tracers 22

Visits by Arthur Kornberg and Herman Kalckar 24

Postdoctoral Positions 26

Deciding Not to Go to the Coris' Lab 26
Postdoctoral Research Fellow with Arthur Kornberg,

Washington University, 1953-1954 27

Postdoctoral Research Fellow with Herman Kalckar, Institute of

Cytophysiology, Copenhagen, 1952-1953 28

Discovery of Nucleoside Diphosphokinase 29

Making Radioactive ATP 30

Life in Denmark 31

James D. Watson 32

More on the Biohazards Controversy 119

MIT Meeting to Discuss Biohazards, 1974 120

The "Berg" Letter, July 26, 1974 121

The Nobel Prize in Chemistry, 1980 122

Singling Out Berg 122

Berg's Opinion of His Best Work 123

Speculations on Why Berg Was Chosen 124

Influences on the Choice of the Nobel Award 127

Yet More on Recombinant DNA 128

Terminal Transferase 128

Creating Permuted Linear Molecules with "Tails" 128

Choosing the Best "Tails" 129

The Jensen et al. Paper and Biochemical and Biophysical Research

Communications 129

The Stanford Biochemistry Department's Industrial Affiliates

Program 132

The Chemistry's Industrial Affiliates Program [IAP] 132

Broaching the Idea of a Biochemistry IAP 133

Stanford Relationships with Industry 134

Program Project Grant, Institute for Research on Aging 134

Sentiment Against lAPs 135

Functions of the Biochemistry IAP 135

Launching Biochemistry's IAP in the Late 1970s 137

Increasing Commercialization of Academic Biology 137

Berg's Prior Refusal of Corporate Consultantships 137

Berg Reconsiders Corporate Connections 138

The Recombinant DNA Controversy 139

Herbert Boyer and Genentech 139

William J. Rutter 141

Cetus Corporation 141

Stanford's Policy on Consulting 143

Policy Reassessment, 1977 143

The Shooter Committee on Conflicts of Interest 145

IV DNAX RESEARCH INSTITUTE OF MOLECULAR AND CELLULAR BIOLOGY, INC. 149

Earlier Commercial Ventures 149

Channing Robertson's Company 150

Alejandro Zaffaroni 151

DNAX 152

Initial Research Focus, Recruitment, Science Advisors 152

Ed Haber and the Engineering of Monoclonal Antibodies 153

Utilizing the Okayama-Berg Procedure 154

Problems in Engineering Monoclonals 155

Fund-raising 156

Schering-Plough and DNAX 157

Schering-Plough1 s Research History 157

Scientists' Initial Reluctance 158

J. Allan Waltz, DNAX President and CEO 159

Tensions between DNAX and Schering-Plough 159

ALZA and DNAX 161

DNAX's Original Product Goal 162

The Shift to T-Cells 163

The Expression Vector Technique 164

Recruitment of Scientists 164

Research Freedom 165

Cloning Cytokine Receptors 166

A Long Discovery Phase 167

DNAX Benefits Schering-Plough 167

Arrival at Stanford, 1959 169

Advance Preparation 169

An Unfinished Science Building 170

Settling In 171

The Stanford Department of Genetics 171

Lederberg's Arrival at Stanford 171
Stanley Cohen's Associations with the Biochemistry

Department 172

Lederberg and Space Biology 173

Faculty and Tenor of the Genetics Department 174

Minimal Interaction between Biochemistry and Genetics 174

Biochemistry's Policy on Joint Appointments 175

Interdisciplinarity 176

UCSF 176
A Consolidated Stanford Graduate Admissions Policy in

Biology 177

Beckman Center Programs 178

Beckman Center for Molecular and Genetic Medicine 179

Origin of the Concept 179

Raising Funds 180

Berg's Strategic Decisions 182

The Program in Molecular and Genetic Medicine 184

Stanford Biochemistry's Asilomar Conferences 185

Greatest Contribution 185

TAPE GUIDE 188

SAMPLE EDITED PAGE 189

APPENDIX

A Paul Berg, CV and Publications 190
B Selections from Berg papers, courtesy Green Library, Stanford

University 208
C "The 1980 Nobel Prize in Chemistry," Science, vol. 210, 21

November 1980 241

INDEX 244

BIOTECHNOLOGY SERIES HISTORY- -Sally Smith Hughes, Ph.D.

Genesis of the Program in the History of the Biological Sciences and
Biotechnology

In 1996, a long-held dream of The Bancroft Library came true with
the launching of its Program in the History of the Biological Sciences
and Biotechnology. For years, Bancroft had wished to document the
history of the biological sciences on the Berkeley campus, particularly
its contributions to the development of molecular biology. Bancroft has
strong holdings in the history of the physical sciences — the papers of
E.O. Lawrence, Luis Alvarez, Edwin McMillan, and other campus figures in
physics and chemistry, as well as a number of related oral histories.
These materials support Berkeley's History of Science faculty, as well
as scholars from across the country and around the world.

Although Berkeley is located next to the greatest concentration of
biotechnology companies in the world, Bancroft had no coordinated
program to document the industry nor its origins in academic biology.
For a decade, the staff of the Regional Oral History Office had sought
without success to raise funds for an oral history program to record the
development of the industry in the San Francisco Bay Area. When Charles
Faulhaber arrived in 1995 as Bancroft's new director, he immediately
understood the importance of establishing a Bancroft program to capture
and preserve the collective memory and papers of university and
corporate scientists and the pioneers who created the biotechnology
industry. He too saw the importance of documenting the history of a
science and industry which influence virtually every field of the life
sciences, generate constant public interest and controversy, and raise
serious questions of public policy. Preservation of this history was
obviously vital for a proper understanding of science and business in
the late 20th century.

Bancroft was the ideal location to launch such an historical
endeavor. It offered the combination of experienced oral history and
archival personnel, and technical resources to execute a coordinated
oral history and archival program. It had an established oral history
series in the biological sciences, an archival division called the
History of Science and Technology Program, and the expertise to develop
comprehensive records management plans to safeguard the archives of
individuals and businesses making significant contributions to molecular
biology and biotechnology. All that was needed was funding.

In April 1996, the dream became reality. Daniel E. Koshland, Jr.,
provided seed money for a center at the Bancroft Library for historical
research on the biological sciences and biotechnology. Thanks to his
generous gift, Bancroft has begun to build an integrated collection of
research materials—primarily oral history transcripts, personal papers,

and archival collections — related to the history of the biological
sciences and biotechnology in university and industry settings. One of
the first steps was to create a board composed of distinguished figures
in academia and industry who advise on the direction of the oral history
and archival components. The Program's initial concentration is on the
San Francisco Bay Area and northern California. But its ultimate aim is
to document the growth of molecular biology as an independent field of
the life sciences, and the subsequent revolution which established
biotechnology as a key contribution of American science and industry.

UCSF Library, with its strong holdings in the biomedical sciences,
is a collaborator on the archival portion of the Program. David
Farrell, Bancroft's new curator of the History of Science and
Technology, serves as liaison. UCSF Library contributed the services of
Robin Chandler, head of UCSF Archives and Special Collections, who
carried out a survey of corporate archives at local biotechnology
companies and document collections of Berkeley and UCSF faculty in the
biomolecular sciences. The ultimate aim is to ensure that personal
papers and business archives are collected, cataloged, and made
available for scholarly research, both in paper form and on the
Internet .

Project Structure

With the board's advice, Sally Hughes, a science historian at the
Regional Oral History Office, began lengthy interviews with Robert
Swanson, a co-founder and former CEO of Genentech in South San
Francisco; Arthur Kornberg, a Nobel laureate at Stanford; and Paul Berg,
also a Stanford Nobel laureate. A short interview was conducted with
Niels Reimers of the Stanford and UCSF technology licensing offices.
These oral histories and others planned or in progress build upon ones
conducted in the early 1990s, under UCSF or Stanford auspices, with
scientists at these two universitites . ' The oral histories offer a
factual, contextual, and vivid personal history that enriches the
archival collection, adding information that is not usually present in
written documents. In turn, the archival collections support and
provide depth to the oral history narrations.

1 Hughes conducted oral histories with Herbert Boyer, William Rutter, and
Keith Yamamoto of UCSF, and with Stanley Cohen of Stanford. The first volume
of the oral history with Dr. Rutter is available at the Bancroft and UCSF
libraries; transcripts of the other interviews are currently under review by
the interviewees.

iii

Primary and Secondary Sources

This oral history program both supports and is supported by the
written documentary record. Archival materials provide necessary
information for conducting the interviews and also serve as essential
resources for researchers using the oral histories. The oral histories
orient scholars to key issues and participants. Such orientation is
particularly useful to a researcher faced with voluminous, scattered,
and unorganized primary sources. This two-way "dialogue" between the
documents and the oral histories is essential for valid historical
interpretation.

Beginning with the first interviews in 1992, the interviewer has
conducted extensive documentary research in both primary and secondary
materials. She gratefully acknowledges the generosity of the scientists
who have made their personal records available to her: Paul Berg,
Stanley Cohen, Arthur Kornberg, William Rutter, Keith Yamamoto. She
also thanks the archivists at the Bancroft, UCSF, and Stanford
libraries, and personnel at Chiron, Genentech, and Stanford's Office of
Technology Licensing, for assistance in using archival collections.

Oral History Process

The oral history methodology used in this program is that of the
Regional Oral History office, founded in 1954 and producer of over 1,600
oral histories. The method consists of research in primary and
secondary sources; systematic recorded interviews; transcription, light
editing by the interviewer, and review and approval by the interviewee;
library deposition of bound volumes of transcripts with table of
contents, introduction, interview history, and index; cataloging in
national on-line library networks (MELVYL, RLIN, and OCLC) ; and
publicity through ROHO news releases and announcements in scientific,
medical, and historical journals and newsletters and via the ROHO and
UCSF Library web pages.

Oral history as an historical technique has been faulted for its
reliance on the vagaries of memory, its distance from the events
discussed, and its subjectivity. All three criticisms are valid; hence
the necessity for using oral history documents in conjunction with other
sources in order to reach a reasonable historical interpretation.1 Yet
these acknowledged weaknesses of oral history, particularly its
subjectivity, are also its strength. Often individual perspectives
provide information unobtainable through more traditional sources. Oral
history in skillful hands provides the context in which events occur--
the social, political, economic, and institutional forces which shape
the course of events. It also places a personal face on history which

' The three criticisms leveled at oral history also apply in many
cases to other types of documentary sources.

not only enlivens past events but also helps to explain how individuals
affect historical developments.

An advantage of a series of oral histories on a given topic, in
this case molecular biology and biotechnology, is that the information
each contains is cumulative and interactive. Through individual
accounts, a series can present the complexities and interconnections of
the larger picture. Thus the whole (the series) is greater than the sum
of its parts (the individual oral histories), and should be considered
as a totality.

Emerging Themes

Although the oral history program is still in its infancy, several
themes are emerging. One is "technology transfer," the complicated
process by which scientific discovery moves from the university
laboratory to industry where it contributes to the manufacture of
commercial products. The oral histories show that this trajectory is
seldom a linear process, but rather is influenced by institutional and
personal relationships, financial and political climate, and so on.

Another theme is the importance of personality in the conduct of
science and industry. These oral histories testify to the fact that who
you are, what you have and have not achieved, whom you know, and how you
relate have repercussions for the success or failure of an enterprise,
whether scientific or commercial. Oral history is probably better than
any other methodology for documenting these personal dimensions of
history. Its vivid descriptions of personalitites and events not only
make history vital and engaging, but also contribute to an understanding
of why circumstances occurred in the manner they did.

Molecular biology and biotechnology are fields with high
scientific and commercial stakes. As one might expect, the oral
histories reveal the complex interweaving of scientific, business,
social, and personal factors shaping these fields. The expectation is
that the oral histories will serve as fertile ground for research by
present and future scholars interested in any number of different
aspects of this rich and fascinating history.

Location of the Oral Histories

Copies of the oral histories are available at the Bancroft, UCSF,
and UCLA libraries. They also may be purchased at cost through ROHO.

Sally Smith Hughes, Ph.D.
Research Historian

Regional Oral History Office
April 1998

Program in the History of the Biological Sciences and Biotechnology

Completed Oral Histories

September 2000

Paul Berg, Ph.D., A Stanford Professor's Career in Biochemistry, Science
Politics, and the Biotechnology Industry, 2000

Arthur Kornberg, M.D., Biochemistry at Stanford, Biotechnology at DNAX, 1998

Niels Reimers, Stanford's Office of Technology Licensing and the Cohen/Boyer
Cloning Patents, 1998

William J. Rutter, Ph.D., The Department of Biochemistry and the Molecular

Approach to Biomedicine at the University of California, San Francisco,
1998

Oral Histories in Process

Horace Barker, Ph.D.

Herbert W. Boyer, Ph.D.

Stanley N. Cohen, M.D.

Daniel E. Koshland, Ph.D.

Marian E. Koshland, Ph.D., retrospective

Reorganization of Biology at UC Berkeley

Edward E. Penhoet, Ph.D.

Robert A. Swanson

Keith R. Yamamoto, Ph.D.

INTRODUCTION- -by Daniel E. Koshland, Jr.

Paul Berg is one of the giants of biochemistry in the twentieth
century. He made crucial discoveries in the area of intermediary
metabolism and then went on to be a leader in the recombinant DNA
revolution. Not only was he a major player in the science but also had
a pioneering role in resolving the ethical and legal questions that were
generated by the new technology.

At a time of increasing controversy, he suggested a moratorium to
allow scientists to digest the benefits and hazards of the new vistas of
discovery and allow the public to appreciate the balance. That calm
moderation in the face of escalating charges and counter charges led to
the peaceful resolution of the issue and the guidelines and legislation
that have allowed biotechnology to flourish.

This oral history traces Paul Berg's career from his childhood in
Brooklyn, through his days as a superstar graduate student (he tries to
say it was luck, but as Pasteur pointed out, scientific luck only
impacts on history if it connects with a prepared mind), to his days as
professor and statesman of biochemistry at Stanford.

The advance of science needs individuals who have the high
imagination to solve the complex puzzles of nature and individuals who
have the wisdom and humanity to resolve the societal perturbations
created by the new discoveries. Occasionally it is fortunate to have
all these qualities in one individual. This oral history records the
events and thoughts of one such rare individual who was a major actor in
the drama of the biological revolution of the twentieth century.

Daniel E. Koshland, Jr.

Professor of Molecular and Cell Biology

University of California, Berkeley

Berkeley, California
July, 2000

vii

INTRODUCTION- -by Charles Yanofsky

Paul Berg is an exceptional scientist and individual who is
committed to improving everything that concerns him. As his oral
history describes, he is responsible for numerous outstanding
scientific, educational, and administrative contributions. Throughout
his career he identified important unsolved scientific problems, and
then proceeded to provide the solutions. But he was not content with
concepts alone. Several of his greatest achievements concern technology
development and improvement. In addition to his scientific advances, he
has made a sincere effort to improve both the support and understanding
of science. Few have accomplished as much of significance as he has.
For his contributions to science he has received numerous awards,
including the Nobel Prize in Chemistry.

I know Paul very well. He and I have been good friends and
colleagues at Stanford University for over forty years. I have
witnessed many of his scientific, educational, and administrative
contributions. We have practiced science and participated in all
aspects of academic life in the same university setting. Our families
have always been very close and have enjoyed sharing numerous social and
other activities. In addition to our interactions with one another,
Paul and I joined Alex Zaffaroni and Arthur Kornberg in founding the
DNAX Research Institute and in guiding its research and other
activities .

If I were searching for a single word to describe Paul based on my
knowledge of his activities and achievements, I would choose the word
savvy. At scientific seminars and group meetings, Paul listens intently
to everything that is presented. He then asks thoughtful and
intelligent questions focused on whatever topic is addressed. In group
deliberations he is not content until each issue is dealt with fairly,
properly, and thoroughly, and at a level reflecting the best thought
that can be applied. He states his views and explains his vision
clearly and emphatically until the wisdom of his position is evident to
all. But he listens to suggestions, and has no difficulty modifying his
opinions or incorporating the ideas of others in his recommendations.
He has a very positive outlook; I am certain that recipients of his
advice appreciate his desire to be helpful.

Paul has played a major role in every enterprise he has become
concerned with. At Stanford Medical School he set the highest standard
as mentor and practicing researcher. He helped recruit many of
Stanford's other "stars," and he introduced several novel courses in our
teaching program. He also is largely responsible for the presence on
campus of the highly successful Beckman Center for Molecular and Genetic

viii

Medicine. He has directed the center since its founding and has
introduced many innovative programs that position researchers at our
university at the leading edge in science. He has also played a
significant role in educating our country's politicians and
administrators on the value of academic research and its potential
benefits to society. He enjoyed teaching the subjects he loves,
emphasizing their promise for the future, and has written several
excellent textbooks that describe our current knowledge in the areas of
biochemistry and genetics.

During his career Paul has had to cope with two exceptional more-
senior scientists, Harland Wood and Arthur Kornberg, each of whom was
always certain that his view was right, regardless of the issue. Paul
has been close to Arthur throughout most of his scientific career and
has learned how to benefit from the genius of this extraordinary human
being. I suspect that there probably is no subject that Paul and Arthur
have not discussed or argued about with one another.

The scientists I know well who have worked with Paul have enormous
respect and admiration for him. He always had the ability to think
beyond their immediate projects and could readily identify the more
significant implications of their studies; routine research was never
his objective. As you will see in his history, his research interests
changed with time, generally reflecting his desire to exploit new and
exciting developments in the areas of science that interest him. But he
could not ignore potential dangers from the actions of the scientific
community, hence his active participation and leadership at the Asilomar
conference that recommended restraints on recombinant DNA research.

In appropriate situations Paul can be very competitive since he is
always determined to do his very best. This was most evident to me on
the tennis court; we played tennis together regularly on weekends for
over forty years. We both enjoyed this diversion as an opportunity to
get our minds completely off science and to compete on even terms.
However, we could not escape our love of science and invariably
discussed our respective research programs with one another, while
sitting on the bench. It was great fun playing against him, or with
him, because of his strong desire to win.

Paul enjoys music, art, the theater, and literature, and collects
and displays his preferences in modern art. Paul's wife Millie, a
lovely woman, understands his dedication to his many activities and
gives him her wholehearted, enthusiastic support. But she also
expresses her point of view emphatically, regardless of whether or not
she agrees with him. They are fortunate that their son John and his
family live close by; they share many interests and activities.

Paul's lifetime experiences undoubtedly influenced his personal
goals and achievements. But success came to Paul Berg because he is

very smart, and he is determined. Few individuals have accomplished as
much as he has. We are all fortunate that someone with his ability has
been so dedicated to increasing our scientific knowledge and improving
our quality of life.

Charles Yanofsky

Department of Biological Sciences

Stanford University

Stanford, California
September 18, 2000

INTERVIEW HISTORY--Paul Berg

The subject of this informative and revealing oral history will be
familiar to virtually anyone in biochemistry and molecular biology.
Even before the Nobel Prize in Chemistry thrust him definitively onto
the scientific world stage in 1980, Paul Berg was a prominent figure.
He had already established a distinguished record in biochemistry and,
more recently, in tumor virus research. He had also risen to
international prominence in science politics as a prime scientific
spokesman in the controversy of the 1970s over the safety and regulation
of recombinant DNA research.

Professor Berg is an old hand at giving an oral history. In the
1970s, he was twice interviewed for MIT's oral history project on the
biohazards controversy, a series noteworthy because it encompasses
interviews with major figures in the controversy as it unfolded and
documents participants' initial ideas about the scientific and
commercial possibilities of the new technology. Because of this
previous coverage, the present oral history accentuates other aspects of
Professor Berg's productive career--his science, his vision as director
of Stanford's Beckman Center of Molecular and Genetic Medicine, and his
affiliation with DNAX, a private research institute (now owned by the
pharmaceutical company Schering-Plough) which he and Stanford colleagues
Arthur Kornberg and Charles Yanofsky founded in 1980. The recombinant
DNA controversy is nonetheless a presence in this oral history, as Berg
reflects on how it influenced the course of research in the field and
his nomination for the Nobel Prize.

Inevitably, when one rises to a position of power and prominence
in science, or any other walk of life, controversy follows. Berg of
course is not immune. There has been debate about the wisdom and
significance of the temporary moratorium which scientists themselves,
with Berg in the lead, placed on certain kinds of recombinant DNA
research in the 1970s and in their formulation of research guidelines.
The award of the Nobel Prize, as is so often the case in its century-
long history, has also been questioned in terms of those singled out for
the honor. ; Berg describes in detail the contributions of his
laboratory to the techniques for joining pieces of DNA by artificial
cohesive ends ("A-T tailing") and how this work relates to that of Peter
Lobban, Vittorio Sgaramella, and, especially Stanley N. Cohen and
Herbert W. Boyer. The reader will likely be fascinated by Berg's
comments on these and other controversial topics.

1 In additon to Berg, the 1980 Nobel Prize in Chemistry went to Frederick
Sanger and Walter Gilbert for the development of DNA sequencing techniques.

There are several surprises in Berg's narrative. One is that he
considers his early research in nucleic acid and protein biochemistry to
be at least as significant as his later work with tumor viruses used as
probes to study the structure, expression, and regulation of mammalian
genes .

A second surprise is that several years before the now-famous
Asilomar Conference of 1975 on Recombinant DNA Molecules, Berg was
sufficiently concerned about the risk of biohazards arising from the
growing technical capacity to manipulate DNA that he organized a
conference on the topic. Most of the participants in the earlier
conference, entitled Biohazards in Biological Research, Berg invited to
attend the later conference.

A third surprise, at least to those not intimately familiar with
the history of recombinant DNA technology, is that Berg makes repeatedly
explicit that he makes no claim to the development of molecular cloning,
an achievement which he openly concedes to Stanley Cohen and Herbert
Boyer. Although Gobind Khorana and others had previously joined DNA
molecules synthetically, Berg claims for his own laboratory the
development of technology for using mammalian viruses to carry foreign
genes into animal cells. The Berg group used this "gene-splicing"
technology from 1972 on to study the dauntingly complex structure and
function of mammalian genes. Berg goes on to describe the genesis of
the Beckman Center for Molecular and Genetic Medicine and its goal of
generating biomedical knowledge which can be translated into clinical
application.

Berg's demanding and sometimes contentious career has in no way
diminished his energetic style and enthusiasm for a diversity of
interests. To this writer, he comes across as friendly, upbeat, and
very likeable. He is also self-confident, assertive, and articulate.
He is widely known in his public and private lives as a concerned
statesman of science and a socially responsible citizen.

The Oral History Process

When I approached Professor Berg in late 1997 about conducting an
oral history, he expressed concern about taking time away from his
project at Stanford's Center for Advanced Study in the Behavioral
Sciences to write a biography, with colleague and friend Maxine Singer,
of the biochemist George Beadle. He agreed to an oral history with the
proviso that the interviews be limited to four. Although we held to

xii

that number, the duration of each interview expanded as Berg became
increasingly engaged in telling his story. My previous research for
interviews with Arthur Kornberg and the review I made of the rich
collection of Berg's correspondence, both collections archived in
Stanford's Green Library, provided institutional context and a basis for
questions. In the discussion of his research contributions, Berg the
educator and translator of science shines through in the clarity and
completeness of his answers, including the diagrams of enzymatic
reactions he created as he reviewed the transcripts. His opinion that
his greatest contribution is to have taught several generations of young
scientists indicates the centrality of teaching in his lengthy list of
accomplishments .

Although an oral history is assuredly not the best means for
determining the factual content of a scientist's research—published
papers, lectures and so on are a far better source--Berg' s clear and
detailed description of his somewhat arcane research is accessible to
readers with only a smattering of biological knowledge. The four
interviews were conducted at Stanford between July 15 and November 5,
1997, the first two in Berg's office in the Beckman Center. The last
two sessions were taped in his study at the Center for Advanced Study,
against a background of the raucous cries of California blue jays in the
oaks dotting the bucolic setting above the Stanford campus. The two
final interviews were interrupted for lunch on the center's sunny patio,
where fellows are expected to gather once a day for scholarly and social
exchange. Berg was characteristically disturbed — an indication of his
sense of social responsibility—that myriad duties had kept him from the
center more often than he had wished.

The lightly edited transcripts were sent to Berg who painstakingly
edited and amended them, despite his distaste for the task. In a letter
accompanying the returned transcripts (a sample of his editing may be
found in the appendix), he remarked: "I thought the ordeal would never
end but it has, I'm sure, much to your relief. Sitting those many hours
with you was a pleasure which is more than I can say about the many more
hours spent reading the transcript: nearly three hundred [double-spaced]
pages was almost more than I or anyone should be expected to bear." The
fact that he not only bore but considerably improved the content and
clarity of his narrative is a gift for which I am, and future scholars
will be, highly grateful and appreciative.

In 1998, Berg retired from his professorship but continues to
direct the Center for Molecular and Genetic Medicine and to be an active
force in American and international science and politics.

The Regional Oral History Office was established in 1954 to
augment through tape-recorded memoirs the Library's materials on the
history of California and the West. Copies of all interviews are
available for research use in The Bancroft Library and in the UCLA

xiii

Department of Special Collections. The office is under the direction of
Willa K. Baura, Division Head, and the administrative direction of
Charles B. Faulhaber, James D. Hart Director of The Bancroft Library,
University of California, Berkeley.

Sally Smith Hughes, Ph.D.

Research Historian and Program Director
July 19, 2000

Regional Oral History Office
The Bancroft Library
University of California, Berkeley

xiv

Regional Oral History Office
Room 486 The Bancroft Library

University of California
Berkeley, California 9A720

BIOGRAPHICAL INFORMATION
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INTERVIEW WITH PAUL BERG, PH.D.

I CHILDHOOD AND EDUCATION

[Interview 1: July 15, 1997]«'

Family and Early Education

Hughes: Let's start with your birth and upbringing.

Berg: I was born in Brooklyn, New York, on June 30, 1926. My mother,

Sarah Brodsky, tells me, a very, very scorching day. The reason I
happen to remember is because she raises it each time we have an
anniversary. It happened on June 30, she will say, "just like the
day you were born."

My parents had immigrated from Russia, and under rather
unusual circumstances. I think it was 1919 that they married. My
mother was eighteen; my father, Harry Berg, was nineteen, and they
left the very next morning, never to see anybody in their families
again. They literally worked their way across Europe over a
period of three years. They had a child and eventually came to
the United States in 1922, I guess it was, arriving in New York
and then settling in New York.

Hughes: Was New York their destiny when they started out?

Berg: I think so, because there were some members of the family, a half
sister, who was living already in New York City. And there must
have been other people who had come earlier from the same little
town that they were from, a village outside of Minsk. So they
formed a local community that knew each other from Russia, or that
knew of each other from Russia.

'//// This symbol indicates that a tape or tape segment has begun or
ended. A guide to the tapes follows the transcript.

My father, I think, worked for other people for a while, and
ultimately started his own little business, which was making fur
trimming on coats and collars and hats and things of that sort.
The boy that they had while traveling in Europe died not long
after they arrived in this country, of what, I don't remember.
And so I was born some four years after they arrived.

We lived in Brooklyn and I can't remember a heck of a lot
about my early childhood. I was told that I didn't speak English
until I went to school, that I spoke mostly Yiddish, which is what
my parents spoke to each other. But once I went to school, I very
quickly almost lost—well, I didn't lose the ability to understand
Yiddish, although I lost the ability to speak it. We lived in
what is now the Brownsville section of Brooklyn, a pretty tough
neighborhood; at that time it was still reasonably nice.

I went through elementary school, probably through the
fourth grade, in that location. I can't remember very much about
school. It was certainly not challenging or that I felt strapped.
It was easy; I enjoyed it; it was fun. And then we moved to a
place in Brooklyn called Sea Gate.

Sea Gate is a small community, which at one time was very
exclusive and very private. It's out at the very end of the
peninsula which forms Coney Island. There's a little peninsula
that comes out from the southern part of Brooklyn, the burrough,
and out at the very tip is this little enclosure called Sea Gate.
In the 1920' s, it was probably quite an exclusive resort, a summer
place for wealthy people to come to, because the homes were very
large.

By the time we moved there, those homes had become more
rooming houses, and it was nothing very special, other than a
great place to grow up. During the wintertime it was literally
empty. So it was a very small community of young people that I
knew and my family knew. In the summertime it was inundated by
summer holiday people. But the beaches were right there, so we
literally grew up at the seashore. I think we moved there before
I reached the fifth grade, because I think I was nine or ten when
I moved there. So that was probably somewhere around the fourth
grade.

Hughes: Did that move represent a rise in the family fortunes?

Berg: No. I can't really remember exactly. We went there for the

summer, again as one of the summer crowd, and I guess my father
and mother liked it so much, they decided to move there. We
didn't have a house; we rented an apartment, and we lived in that
apartment. I then finished elementary school in Coney Island.

There were no schools in Sea Gate, so you had to walk; it was
probably half a mile, something of that length.

I graduated from that school and started junior high school.
Today, it's called middle school, I guess. It was the seventh,
eighth, and ninth grades. I had done very well in school; I had
skipped grades twice during this period. I guess that's not
common anymore. I forget which ones I skipped, but by the time I
was in the sixth grade and went to junior high school, I was
already a year ahead. There I entered rapid advance classes,
which took the seventh and eighth grade in one year. So you took
7A and 7B in one half year, and 8A and 8B the second half of the
year.

That was one of the exhilarating periods of my life. The
people who were selected to participate in these rapid advance
classes were all very bright and very energetic, and so it was an
exceedingly exhilarating period. Because the teachers didn't have
to worry about people who were slow in picking up on things, you
could do things in that class that you couldn't do in ordinary
classes .

Hughes: Do you remember being interested in anything in particular?

Berg: I was interested in science right from the beginning. Even before
junior high school, I was interested primarily in biology. I was
interested in trying to understand living things. Every time I
found any kind of an animal that had died, I took it home to
dissect it and see what I could learn about it. I knew that
biology was the focus; that was the thing I wanted. Probably at
that early stage, it was translated into an ambition to be a
doctor.

From the things we read during this junior high school
experience, there was a lot of motivation and idealization of
being a physician, or a research physician in particular. I ask
my students today how many have read Sinclair Lewis's Arrowsmith
or [Paul] de Kruif's book, Microbe Hunters. None of my students
have ever heard of either one of them, which is a disappointment.
But the key figures that were created or converted into idols were
physicians who were doing research and solving major health
problems. So I had in mind that I probably wanted to be a doctor,
but I didn't necessarily think of it as practicing medicine as
much as doing research in medicine.

Hughes: What did your parents say about all this?

Berg: My parents had never had any formal schooling. They left this
small town before they had any significant amount of schooling,

other then probably just grade schooling. They could read and
write. But there was nothing but encouragement, nothing but
strokes, lots of admiration. They knew I was doing well. They
never ever queried me about what I wanted to be or anything like
that. They just took great pleasure in having their son being
successful in something which they regarded as very, very
important—education at a very high level—even though they never
had it.

I think that was true of many of the immigrant Jewish
families. Education was put on a very high level, even though the
parents had little of it themselves. My wife, Mildred Levy, says
today, because she met my parents when we were married, "You were
so fortunate, because your parents not only encouraged you, but
they gave you enormous positive feedback. So all the while you
were extremely secure in what you were doing, feeling good about
it. Without their bragging about it or anything like that, you
just knew you were doing well. Your parents thought well of you,
and that was great. You didn't have to impress them."

Abraham Lincoln High School

Berg: At the same time, I was very active in sports and very much

involved in playing football. Whatever the sport of the season
was, I was actively involved. And so when 1 went to high school,
I really wanted to play football as well as do what I had to do in
school. But because I had skipped so much, I was really much
younger than people who were at the equivalent level in school, so
I wasn't as fully physically developed. I think I was undersized
and would probably have gotten killed if I went out to play
football.

Hughes: You were how old?

Berg: I graduated in January of 1943. So I went to high school three
years earlier than that. That's 1940, so I was not quite
fourteen. And high school was fun. I didn't take it seriously.
I wasn't intensely focused on books. I just found it easy, and I
could do lots of other things.

But all that time I was very interested in biology. The
biology course was one of the really exciting and interesting
things we did in junior high. We did a lot biology. Because of
the quality of the students, we did all kinds of projects.

Hughes: What about the quality of the teachers?

Berg: My recollection is that the teacher that we had in junior high

school for the rapid advance classes was magnificent. She really
knew how to handle gifted kids. She didn't hold us back. She
encouraged us. 1 don't remember so much about her, or him, I'm
not even sure which one it was.

The teacher in high school had a very different style of
encouraging young people. We were given lots of projects to do,
and the projects were to be done at your initiative, and you
weren't given a lot of help. There was an enormous amount of
interchange amongst the students in the class, and we all knew
each other. Many of us were growing up in the same little
community. We always regarded ourselves as a special group,
because we lived together during the winter when nobody else was
there. And we were the "in" crowd, the real crowd.

During the time I was growing up, we had a football team, on
which I played. We played in a league, and we played tournaments.
My brother, Jack, who is a year and half younger than I am, was
also on the football team, and also was a very good student. We
were very close.

Hughes: Just the two of you?

Berg: We had a third brother, Irving, who was five years behind me. At
that age, I think, we had nothing to do with him. There was just
Jack and myself.

When I went to high school, I took all the science courses
that were available. But, again, I don't remember knocking myself
out; I certainly wasn't an honor student; my name isn't on the
board as one of the great students — like Arthur Kornberg's name is
there.1 We went to the same high school. I couldn't play contact
sports, because I was not up to that. So I just played the kinds
of sports we did at home.

Sophie Wolf

Berg: There was a woman, Sophie Wolf, who was probably one of the more
important figures in my life in terms of motivation. She was not
a teacher, but she ran the supply room for providing the

1 See Arthur Kornberg, Biochemistry at Stanford and Biotechnology at
DNAX, Regional Oral History Office, The Bancroft Library, University of
California, Berkeley, 1998.

demonstrations and the microscopes for biology and the models for
various lectures. There was this very large stockroom, which had
an enormous amount of stored resource material—microscopes , and
models of different organisms, and things of that sort.

She had a keen interest in young people. She ran what was
called the Biology Club, which met in people's spare time, after
classes were over. And so 1 used to spend the afternoons there at
the Biology Club. One of the terrific things about her was, she
never gave you any answers, no matter what you asked her. She
would come back with a leading question that would perhaps help
you go find out on your own. This even included doing
experiments, so that if you asked a question which she thought you
could answer by actually doing an experiment, she would help you
to find out what kind of an experiment you might do. But in the
end, it was your drive that led you to do those kinds of
experiments. I think during the two or three years that I was in
involved in this club, she was constantly stimulating us with
questions and leading us on to trying to learn new things.

Interestingly enough, Sophie was also there at the time
Kornberg was a high school student. At the time I got the Nobel
Prize [1980], somebody asked me if there was any notable person
who played a key role in stimulating me, and I mentioned Sophie.
I thought she was long since dead, but as it turned out she was
retired and living in Florida. The education reporter for the New
York Times wrote a very long article, because it was unusual for
anybody to identify a high school -figure as being such a key
person. Usually, people identify a university professor who
played a key role in moving them along. She then literally came
out of anonymity and became quite well known.

Subsequently, a third person from Abraham Lincoln High
School got the Nobel Prize, in addition to Kornberg who received
the prize in 1959, a man by the name of Jerome Karle, who did some
very magnificent work in crystallography. So some time ago, I
forget exactly what year it was, they decided to name the science
wing of the high school—it was a very large high school—the
Sophie Wolf Wing. And one floor is named the Paul Berg floor, and
the other one is Arthur Kornberg, and the other is Jerome Karle.

They had this huge assembly; all the students were gathered
in this large auditorium, and the mayor and the secretary for
education, or whatever it was, for the City of New York came. And
there was little, old, wiry, Sophie Wolf, who was pretty far out
of it most of the time, but she just lapped up the accolades.

Hughes: There can't be too many individuals at the high school level who
are able to boast of mentoring three Nobel prize winners.

Berg: I don't know if it was the only high school in the U.S. that has
had three Nobel graduates, maybe the Bronx High School of Science
or Clinton High School, which were also very academically
oriented. But my school was not specially notable for its
academic achievements. It was big. It was located in an area
called Brighton Beach, which was quite a way from where I lived.
We needed a bicycle, or in the wintertime there was a bus that
took us, and sometimes we even walked. It was probably three to
four miles.

Hughes: How did Sophie Wolf get her scientific knowledge?

Berg: I think just on the job. I don't know how she got into that role.

The high school opened in 1930. I think Kornberg moved to
it from another high school because it was closer to his home.
And 1 think he only went there the final two years of his high
school stay. He graduated high school at a very young age. I
think he graduated from City College when he was sixteen. So,
it's conceivable that he went to high school when he was twelve or
thirteen.

But in any case, Arthur acknowledges the impact that Sophie
Wolf had. Jerome Karle did as well. She not only was for
biology, but she managed the storeroom for all the demonstrations
for physics, chemistry, and so on. I don't know whether she had
any science background at all. She must have been there right
from the beginning when the school opened. But it was a central
role, because she saw all the science students. And for anybody
who expressed an interest, she would invite them to join one or
another of the clubs that she had.

Hughes: It had to be by her invitation?

Berg: Well, either an invitation or encouragement, one or the other.

Anyway, while I was in high school, Pearl Harbor occurred.
I graduated in 1943, and I remember very clearly the big assembly.
The school was assembled in this large auditorium to listen to
President Roosevelt condemn this "act of infamy" and then declare
war. So my last year or year and a half in high school, we were
very much taken up with the war, and what we were going to do, and
how we were going to participate. I had made up my mind that as
soon as I turned of age, I was going to enlist in the navy. I
graduated in 1943, so I was sixteen and a half. Almost
immediately after I graduated, a friend of mine and I enlisted in
the navy air corps, the navy flight program, and we were to be
called up somewhere.

II COLLEGE, GRADUATE, AND POSTGRADUATE STUDENT

Chemical Engineering Student at City College of New York

Berg: In the meantime, I certainly had the ambition to go to college.
My family wasn't well off enough to allow me to go wherever I
wanted, so I went to City College in New York, which was free if
you had the appropriate grades. And so I was admitted to City
College. Now I can't understand why, but at that time I set out
to be a chemical engineer. Quite different than all this medical
ambition I grew up with. I don't know who prompted me to think
that going into medicine was difficult for a Jewish guy at that
stage. I know Kornberg himself had the same reservations, the
same concerns, and the same warnings.1 Chemical engineering was
something that was practical, was something that you could easily
count on as a career and for making a living.

Anyway, that whole thing at City College lasted three days.
Because from where I lived, which was at the southern tip of
Brooklyn, it took me, to go to City College in upper Manhattan,
almost three hours to commute one way, two and a half the other.
I was committed to being a chemical engineer, but I had already
enlisted in the navy, and I knew that they were going to call me
sometime.

The procedure at City College for registering for classes
was about as baroque as anything you could possibly imagine.
There was a certain number of courses that were available. And in
one room of this immense hall, they had all the courses listed up
on a board. As soon as a sufficient number of students had
registered for that course, they took it off the board. You tried

1 For Kornberg 's view on anti-Semitism, see Arthur Kornberg,
Biochemistry at Stanford and Biotechnology at DNAX, Regional Oral History
Office, The Bancroft Library, University of California, Berkeley, 1998.

to make up your schedule sitting in a room three hundred yards
away from a printed schedule. After you made up a schedule, you
got in a queue, and you walked through this line being badgered
all the while by the ROTC [Reserve Officer Training Corps] people,
trying to make sure that you had enlisted in the ROTC. And when
you got to the tally, they would look up on the board, and if the
course was closed that was it. So I spent two days of never
getting a schedule.

Finally, for those that were left over, you took whatever
leavings there were. And so, I would have a course at eight
o'clock in the morning, and another one at one o'clock in the
afternoon. Of course, coming from a place that was two and a half
hours away, an eight-o'clock class meant I left home at the crack
of dawn. So, I did that for three days, and 1 decided it wouldn't
work.

The first class 1 went to was a physics class. Now, I had
come from a high school which was not specially oriented towards
science, certainly not to the extent of several special high
schools in Brooklyn at that time, one of them called Brooklyn
Tech, which was very much oriented towards people going into
engineering or science. As high school students, they had already
had many of the kinds of courses that anybody else would take when
they went to a university.

In the first physics class I sat in on, we were given an
exercise to make some measurements. They were trying to teach us
something about the variables in making repetitive measurements
and how to determine the significance of the measurements. There
were these blocks of wood on the table, and some kind of a tool
that I had never seen before, and a data pad. I was told to start
making these measurements, and I didn't even know what this tool
was or how to use it. I looked over at people sitting on either
side of me, and they were going ahead and measuring. When I asked
somebody if he could show me how to use it, I got brushed off very
abruptly. So it was clear that the atmosphere there was very
intense, highly competitive, and I would say certainly not
friendly.

Biology Student at the Brooklyn College Campus

Berg: I didn't like the prospect of continuing that for I don't know how
long, so I withdrew, and I went to another of the City Colleges,
which is the Brooklyn College campus, much closer to home. I
enrolled as a biology major, since I knew chemical engineering was

definitely not what I wanted. Especially since in one of the
lectures, somebody talked about what chemical engineers do, which
was building factories to manufacture various kinds of chemicals,
and designing the machinery for carrying out certain processes. I
realized that was not what I wanted. I actually was more
interested in bench research. So, I decided I would go into
biology.

Biology was exceedingly disappointing. It was the classical
thing where you dissect some little pickled guinea pig or
something, and then make exotic drawings of everything in it.
Totally, totally boring. And so there I was, really disappointed.
I didn't like the chemistry; I didn't like the biology—what to
do?

Biochemistry Student at Pennsylvania State University, 19A3-19A8

Berg: At that time a friend of mine, who also lived in Seagate and was
an engineering student, went off to Penn State. He sent me a
catalog of Penn State, and I thumbed through it, and lo and
behold, there was something called biochemistry, the Department of
Biochemistry. This was not chemistry and it wasn't biology, but
it looked like it was what I was really interested in the
processes that go on in living organisms. So, 1 decided to go to
Penn State.

Now that I think about it, I think I graduated in January,
1943, and attended Brooklyn College in the spring term. That
summer, which would be the summer of 1943, I turned seventeen, and
I was allowed to enlist. I went off to Penn State, waiting for

the navy to call me.

Hughes: Was it a full department of biochemistry?

Berg: Yes.

Hughes: That was a bit unusual.

Berg: It was unusual. But it was not unusual, because it was in the
Agriculture School, which is where biochemistry was largely
centered in the thirties and forties. Most of the focus of
biochemistry at that time was on analytical chemistry of
biological materials. The people that came out of that program
generally ended up in the pharmaceutical industry or in the food
industry. In fact, while I was going to college, I was working

summers in food companies, in their research labs, doing what they
call today food technology.

The other kind of biochemistry was largely in medical
schools, and it was generally called physiological chemistry. But
I didn't know this Department of Biochemistry was in the ag
school. It didn't make any difference because within a few months
I was called up in the navy. So, I completed one semester at Penn
State as a freshman student majoring in biochemistry.

Military Service in World War II

Berg: It was the navy procedure to send you back to the university for
further training. If you had already been to the university, you
were permitted to continue in whatever you had been studying, and
doing in addition the few courses that the navy wanted you to
take, which were navigation and a few different engineering
courses. If you had never been to the university before--

Berg: --you were immediately sent to a place and put into an engineering
curriculum. People generally stayed in these places for about a
year, before they were to go on to the next stage of the flight
training program.

Hughes: That was a stroke of luck.

Berg: That was a big stroke of luck. Originally, I was sent to
Middlebury College in Vermont. But I knew that the usual
procedure was that if you had already started at a university, and
it had a navy unit, you were usually sent to the place where you
had been. So, I wrote to the navy and asked them if I could be
reassigned to Penn State, which I was. So when I went back, I was
wearing a navy uniform, and I lived in a navy barracks on the
campus. All the courses that I took were the same courses I would
have taken had I been a civilian, and that was fortunate. I did
that for three semesters, I guess it was, one entire calendar
year.

By that time it would be late 1944; the navy decided that
the attrition of navy pilots was far smaller than they had
anticipated, and so many of us were transferred from the navy
flight training program into what they call the deck officer
school. I was sent to a midshipman school to be trained for ship
duty. And that was in New York City out on Long Island Sound, a

place called Fort Schuyler. We were what people came to call the
ninety-day wonders. You went for three months and you were
commissioned as an ensign in the navy.

I was assigned to a sub chaser program. And I went off then
to this place in Key West which trained officers for duty on
submarine chasers. Those kinds of ships that I was on did either
convoy duty, which was to protect maritime shipping, chasing
submarines, or controlling landing ships during an invasion. So,
I didn't get to do what I wanted to do, which was why I enlisted;
I wanted to fly, but I ended up in the navy doing sea duty. I
stayed in the navy until after Hiroshima. Then I spent one year
bringing ships back from the Pacific and various parts. In the
summer of "46, I was released from the navy.

Hughes: You were in the Pacific?

Berg: Yes, and also I was on ships that were protecting convoys in the

Caribbean. I don't think that most people really ever appreciated
how much American shipping was lost to the German submarines that
were literally stationed off the East Coast and particularly the
Caribbean, because there was a lot of traffic through the Gulf of
Mexico. They devastated American shipping.

Our job was to try to reduce that devastation. By that
time, of course, the navy had already broken some of the German
naval code. They knew where the submarines were, and so it wasn't
quite as devastating. Britain came very, very close to losing the
war early on, because supplies to them almost never got there, it
was so bad. Until they broke the naval code, which is a story in
itself, they were on the verge of desperation. But once they
broke the code, they knew where the German submarines were, and
they were able to avoid them.

When the war ended, there were a lot of ships that had to be
brought back from the Pacific. And so we brought them back, and
then took them into what they call mothballing; storing them in
various tributaries. And then they just covered them over with
this protective covering to presumably preserve them. I was
released, as I say, in the summer of "46, and went back to Penn
State that fall.

Return to Penn State

Marriage

Berg: Although I had been in the navy for close to three years, I hadn't
really lost that much time. I only had two years to finish
college. And I did that, and finished with a major in
biochemistry. I got married somewhere along the line, actually at
the end of the junior year [1947], to somebody I had known for
years and years, although she was not from where I grew up.
Millie and I had worked together one summer in New York City in a
company in which her father was one of the executives, and 1 was
the office boy, and she was the mail clerk. [laughter] I was
sixteen and she was fifteen.

Hughes: That's quite a story.

Berg: We kept in touch with each other while I was in the navy, and when
I came back to New York, sometimes we'd get together. But after 1
got out of the navy, we established contact and then we were
married the next year, in 19A7. So we're coming up to our
fiftieth wedding anniversary this fall.

Decision to Do Graduate Work in Biochemistry

Berg: Those two years at Penn State were rather interesting, because

that's when I really started doing biochemistry in a serious way.

Hughes: Why?

Berg: First of all, I was a little older than I would have been had I
just gone straight through. I was married now, and really much
more focused on getting out of school. I knew I wanted to go on
to graduate school. I didn't know where or how. I had decided
that medicine was not what I wanted to do. I did want to do
research.

At the end of my junior year, I worked for General Foods
Corporation, over in Hoboken, New Jersey, in their research labs,
doing just standard analytical work. The following year, I worked
at the Lipton Tea Company in their research laboratories, also in
Hoboken, again doing largely food technology.

Hughes: What effect did those summer jobs have?

Berg: Well, the summer jobs had one strong motivating force. You could
see that the people who had bachelors degrees were the ones who
were being told what to do. And the people who were telling them
what to do were people with Ph.D.s. Very quickly that was the
deciding point, that if 1 was going to go into science, I did not
want to be in a position where people were telling me what to do.
I wanted to be able to drive the research myself. And that's when
I decided that I wanted to do a Ph.D. So it was the end of the
junior year, when I knew I was going to go on to graduate school.

My wife was a registered nurse. In fact, during the war she
had been in nurses training. And when she graduated in 1947, we
were married. She went back to State College, which is where Penn
State is. State College was a town of about three thousand
people, a dinky little place—no hospital. We were living in a
rented room in somebody's rooming house. She tried to find a job,
and a hospital was twelve miles away. We had no car. She
obviously couldn't do that. So she worked for a while looking
after newborn babies born to student wives during the first weeks
after birth. That was clearly not satisfying. So she went back
to New York City, lived with my parents, and worked in a local
hospital there. So for that last year, we were separated. 1 used
to commute back and forth from State College, about an eight-hour
train trip, to New York for the weekends and then go back on
Sunday nights. And that was a hassle.

During my last year, again, my performance in school was
pretty good. I was identified pretty quickly as a bright young
student to be helped. I wrote several papers, not for
publication, but during my last year, 1948. One of them was about
the newly emerging use of isotopes for tracing metabolic
reactions, and that excited the heck out of me. I gave several
talks on it.

Graduate Student. Western Reserve University, 1948-1952
Applying to Graduate Schools

Berg: So I applied to this one school, which seemed to be the place from
which many of the review articles and published papers were
coming. It was Western Reserve University, a place I had never
heard of. I thought it was an Indian reservation. I wrote to

them, and they didn't have an opening for a new research
assistant, a graduate student.

Hughes: Who was there?

Berg: A man named Harland Wood.

Hughes: He was the one using the isotopes?

Berg: He had just created a new department. I'll come back to that in a
little bit, because it's a very important part of my life.

During that last year, knowing that I wanted to go to
graduate school, I approached it in my typical way, which is, I
got a book about all the graduate schools that had biochemistry
departments, and I wrote a letter to each one of them applying for
admission. I must have sent out about sixty letters.

It was the same way I got the summer jobs. I would write to
every chemical, biology, drug company, food company in the New
York Metropolitan area, and just wait for an answer. [laughter]
And I always got an answer offering me a job for the summer. And
so I did the same thing for graduate school, just applying to a
large number of places. Not unexpectedly, some of them had
biochemistry departments in the medical school, others in the
agriculture school.

So, I applied to Western Reserve; it was one of the many
that I applied to. It's an interesting fact relating to
Kornberg's talk about anti-Semitism: I'd get back some letters
which were offering me admission into the graduate program in
biochemistry, with a warning or statement telling me that by no
means should I consider this as a possibility that I would be able
to enter the medical school through the back door. They were
really quite up front about that.

Eventually, I chose to go to a place called Oklahoma A and
M, which today is called Oklahoma State University. For a guy
from Brooklyn to choose to go to Oklahoma A and M was already
pretty radical. [laughter] But part of the reason was the
department of chemistry offered us a place to live, found a job
for my wife to work in the local hospital, and they were really
recruiting heavily. So I agreed to go.

Hughes: You went for those somewhat peripheral reasons, not for the
science?

Berg: That's right. It was known as a pretty good school of chemistry,
but I didn't know a lot more about it. And so I accepted.

Decision to Attend Western Reserve University

Berg: Within about two weeks of the time we were going to leave Penn
State, and planning to go west, I got a call or letter from
Western Reserve saying that they now had an opening, and they had
money, and if I would like to come, it would be worked out. I was
very, very troubled because I had already accepted this very
generous offer from Oklahoma A and M, and I remember being very
troubled about turning it down.

I went to see both the dean and the chairman of the
biochemistry department at Penn State, and to this day, I can
never thank them enough for having said, "Look, just call up
Oklahoma A and M and tell them straight off that you've had your
mind set on doing this kind of work, and here was an opportunity
to do that." I did that and they were extraordinarily gracious.
I was so bowled over, because it was so unexpected. I thought
they would give me a hard time by saying how much difficulty they
had gone through to get me settled.

The Department of Clinical Biochemistry

Berg: In any case, when I got to Western Reserve in Cleveland in 1948,
what I found is that I had been accepted by the wrong department,
[laughter] In fact, what I had actually applied to was an ad in
the Chemical and Engineering News, in the back section where they
printed job openings. And it said, "Western Reserve University,
Department of Clinical Biochemistry, Medical School." And since I
recognized that Western Reserve University was the place from
which all these papers were coming that I was so excited about, I
just assumed that they were one and the same.

The biochemistry department at Western Reserve University
had been headed by a man, Victor Meyers, since 1915 or "20, who by
1948 was literally senile and long since beyond any period when he
had been productive. When the war ended, Western Reserve
University realized they had to rejuvenate the biochemistry
department . So they recruited from Iowa what was then one of the
hottest young biochemists in the country, named Harland Wood. He
brought his entire group from Iowa, and several people who were in
Minnesota. He created a department essentially in one fell swoop.
What to do with the man who had been head of the department? They
created Clinical Biochemistry, of which Victor Meyers was the sole
occupant.

So, when I got there, I was told I was going to be in this
department, and I realized that it had nothing to do with the one
I wanted, which was on the floor above. But there wasn't much I
could do; I was there. And when I went to see Victor Meyers to
discuss what I was going to do, he gave me a couple of old theses,
which were by people who had analyzed cholesterol levels in
various tissues of autopsied individuals. And my assignment was
to do the cholesterol level in some eighty-five postmortem heart
muscles and see if I could correlate cholesterol level with cause
of death. Well, that was pretty discouraging.

Research on the Artificial Kidney

Berg: Fortunately, Meyers died about a month later, and so there I was
stuck in this pseudo-department. But two of Meyers' earlier
students were working in the lab, and one of them, Jack Leonards,
had been given a junior appointment in the department of
biochemistry, largely as a courtesy. He asked me if I would be
willing to stay on and work with him. Well, I didn't have much
choice, so I said yes.

It turned out that he and this other person, Leonard Skaggs,
who had also been a former student there, were developing an
artificial kidney. At that time there was already a precursor,
which had been developed by a Dutchman named Kolff, and which was
in use, but was very, very complicated. It was a big rotating
drum around which dialyzing tubing was wrapped, and blood ran
through the tubing, and this drum rotated it through a bath which
allowed dialysis to occur. So toxic substances that were in the
blood could pass through the membrane into this bath.

These two guys had come up with a design which was sort of a
neat little box. It was a very ingenious idea. And so I said, I
have nothing to lose; I'd work for them. So I started to use the
artificial kidney to learn how to keep animals alive after you've
taken their kidneys out. I had to learn a lot of surgery and
things I wasn't terribly interested in.

Joining the Department of Biochemistry

Berg: Meanwhile, I was taking courses that graduate students had to

take. All the courses were in the biochemistry department, plus
the first two years of medical school courses. Well, one of the

courses I had to take up in the biochemistry department was a
course in which students were asked to give presentations on
current research papers, and I gave one or two of them. And not
long afterwards, I was approached by the chairman of the
department: Would I consider moving up into the biochemistry
department? Well, that was the kind of thing you'd say, "I
thought you'd never ask."

So, at that point, I went to these two fellows and told them
that I had always had my heart set on working in this lab where
there was use of isotopes, and not on this type of physiological
chemistry that they were doing. They were very good about saying,
"By all means, go." And so I moved up to the department and
became a graduate student there.

I had already spent two years in this process and at that
time a Ph.D. program was normally four years. People did not take
longer. And so I essentially did my thesis research in two years.
Our students today take five, six years and don't do half what we
did, because we had to teach, and we had to run the laboratories
for the medical students and take a lot of courses. We had to
take almost the entire curriculum for the first two years of
medical school, even though we were not going to go on and be
doctors .

Harland Wood and the people in the department were different
role models than anything I had seen. First of all, it was an
academic setting. It wasn't an industrial lab. And the pace of
discovery in my research went extremely well. I received a lot of
kudos and gave talks at national meetings, and so on. The
feedback I got was that I could do this; this is a career that I
could be successful in. And it looked like it was great fun, to
just go into a lab and be able to do whatever you wanted.
Teaching was not a difficult thing, and jobs were plentiful.

Hughes: So, you were teaching while you were learning.

Berg: That's right.

Hughes: You hadn't had much formal biochemistry, had you?

Berg: Well, what we did was teach in the laboratories. Biochemistry

courses had laboratories associated with them. Medical students
had to go in and carry out various exercises. There were maybe
twenty or thirty experiments over a term, and you were there to
help them. We had to set up the reagents for them. We had to
test the experiments to see if they would work, and things of that
sort. And we had to spend long hours in the laboratory with the
students. And then when the laboratory was over, we could go and

work. The general pattern of working for a graduate student is
essentially into the wee hours of the morning.

My wife was a nurse at Western Reserve Medical Center, a big
hospital which was part of the medical center. And she chose to
work some very interesting hours, like six to midnight. That
meant she had the day free, and I could go back in the evening and
work until midnight. And then I'd go pick her up from the
hospital, and then we'd go do something sometimes. That was a
very good thing, because the hospital had a hard time getting
people to work those hours, so she only had to work six hours and
was paid for eight, which was nice. She largely supported the two
of us. I was on the G.I. Bill, which I think was something like
$165 a month. I don't know, her salary was maybe twice that. And
so we lived on that.

We had an apartment very near the medical center, so we
could both walk to the lab or to the hospital. We spent four
years in Cleveland, which actually was great fun. We really
enjoyed it, made a lot of friends. The principal thing about it
was, it opened up new vistas for what I wanted to do.

Research on Nutritional Supplements

Hughes: What was the research?

Berg: It was to solve a problem that had really been a central theme or
problem in biochemistry. Animals on certain diets, for reasons
that nobody could tell, would die. Well, that's not a very good
explanation. There were certain compounds or nutrients that were
thought to be an essential part of every person's diet. And if
you left them out of the diet, they led to death. One was the
amino acid, methionine, and a compound called choline. If
methionine was omitted from the diet, animals usually developed
very fatty livers and then ultimately died.

About the time that I was plugging away at dialyzing
animals, one of the great figures in biochemistry, a man by the
name of Vincent du Vigneaud, was a professor of biochemistry at
Cornell Medical School, and later received the Nobel Prize [1953].
He was one of the ones that had reported that methionine was an
essential part of the diet. But there were hints that this wasn't
necessarily always true, because if you varied the diet,
supplemented it with certain vitamins, you could leave methionine
out, and the animals did fine. The two things were folic acid and
vitamin B-12. When you looked in the tissue in the diet, what you

found is that the animals contained methionine and choline which
previously had to be supplied in the diet. So, it was obvious
that given these vitamin supplements, they were able to completely
synthesize these molecules, which had been thought to be unable to
be synthesized.

There were already some indications of what kind of
molecules could be used as the building blocks to build methionine
and choline. One of the people, Warwick Sakami, in the
biochemistry department where I was had done an experiment
injecting radioactive formaldehyde into rats and then recovering
methionine and choline from their livers. He showed, using this
radioactive formaldehyde, that the methyl groups of methionine and
choline had been produced using the formaldehyde.

One of the great, great things about using radioisotope
tracers was that you could feed a molecule that was marked
radioactive, and you could determine whatever it ended up in, the
new molecule because it contained radioactivity. So, formaldehyde
had been converted into the methyl groups of methionine and
choline. And so, it looked like these animals, when provided with
the appropriate vitamins, were actually able to convert the one-
carbon compound, formaldehyde, and subsequently formic acid and
methyl alcohol. All three of these, in fact, could eventually be
converted in the body to the methyl groups of methionine and
choline .

Berg's Initial Research Project

Berg: In one of the seminars, when I was still a student in Clinical
Biochemistry, 1 reported this progress. And in preparing the
seminars, it came to me that there were certain kinds of
experiments that could be done that would test how this synthesis
went. And so, I went to Warwick Sakami, in biochemistry, and I
told him that it seemed to me that one could find out something
about this process, by the following kind of experiment. And
that's when he said, "How would you like to come up here to the
biochemistry department and do it?" And then he went to the
chairman of the department, and Harland Wood then asked me if I
would be interested in coming up. So, when I went up, I did this
experiment, and it came out beautifully, describing for the first
time how this one-carbon molecule could get into these other
products .

Hughes: So they were intrigued by the science that you proposed to do.
But were they also impressed by the fact that you were using a

technique that Harland Wood was interested in, namely the use of
radioisotopes?

Berg: Everybody in the department was doing that.
Hughes: Using radioisotopes.

Berg: Using radioisotopes. So, I didn't bring anything novel to the
idea of using radioisotopes. It was more how to use the
technology to actually explain an interesting and at that time
unknown biological process. So my recollection of what they said
is, "That's a neat idea. Why don't you do it?" So, I went up and
set up the experiments and actually started to do them. And as I
say, they came out pretty much the way I predicted.

That then led me to try and do enzyme experiments, asking
could we demonstrate the enzymes that carry out this process?
Well, at that time, I wasn't very much of an enzymologist . All I
could do was set up these tissue extracts. They were relatively
crude extracts. But we showed we could convert formic acid or
formaldehyde to the methyl groups of methionine and choline in a
cell-free system.

Hughes: Was that something that people with a biochemical background would
have known how to do?

Berg: You mean how to do the extracts?
Hughes: Yes.

Berg: Yes, doing that was not so novel. Kornberg was doing enzymology
long before that. People were studying how one-carbon compounds
are used to make purines in nucleic acids. So, what I did was
actually set up for the first time an in vitro system that could
actually manufacture methionine and choline, and I used these
radioactively tagged molecules to show how that conversion went.
I was able to show that in fact in these extracts there was
evidence that you needed cof actors, so-called, which were derived
from folic acid, which had been hinted at by showing that animals
fed high levels of folic acids and B-12 could make everything.
So, it was not terribly surprising. I published several papers on
that.1

1 For references throughout the oral history to Dr. Berg's
publications, see his bibliography in the appendix.

Countering du Vigneaud iti

Berg: One of the things that happened was, I went to a national meeting,
and when I presented this work, Professor du Vigneaud, this man
who had been the real honcho for this whole field, got up and gave
me a hard time. He had been protecting the principle and concept
that these substances were required in the diet. And here was
somebody getting up and showing that they were not only not
required, but here was a way in which they could be made in the
body.

I must have handled myself very well in this debate, because
plenty of people told me about it afterwards. But interestingly
enough, du Vigneaud went to Harland Wood and said, "You have a
young professor in your department, Paul Berg. I want to offer
him a job here at Cornell in New York." And Wood told him, "He's
not a professor; he's a graduate student." [laughter] So, my
work really flourished; it went very well. And by the time I was
ready to go, I was already known somewhat outside Western Reserve.

Harland Wood and Radioisotopic Tracers

Berg: Now, there was a steady parade of distinguished people who came
through Western Reserve because Harland Wood was one of the very
leading top people in this field. He had developed whole new
approaches to studying metabolism using these isotopes. And he
had invented instruments that made it possible to study both
radioactive and stable isotopes — stable isotopes like carbon-13.
He had built a mass spectrometer to do this kind of analysis. He
was a remarkable guy.

Hughes: Postwar, radioisotopes were relatively easy to obtain?

Berg: Easy to obtain because Oak Ridge Laboratory was cranking them out,
and they were commercially available. Radioactive isotopes
carbon-14 and P [phosphorus] -32 were available. The other
isotopes were much harder to get, but they too could be obtained,
because they were made by some form of enrichment. Carbon-13 is
normally present in carbon dioxide. But it's present in only
small quantities, and nitrogen- 15 is present in all kinds of
nitrogen-containing compounds, again, in small quantities. During
the war they learned how to enrich for these heavy isotopes, as
they were called. And the radioactive isotopes were made in a
radiation lab.

During the war, before radioisotopes were available, Harland
Wood was restricted to using carbon- 13, and he did one of the
great, monumental pieces of work in discovering that carbon
dioxide is actually metabolized. We build lots of our organic
molecules from carbon dioxide that we had always considered as a
waste product.

If you label the carbon dioxide and feed it to animals, you
can show that they in fact make many complex molecules from the
carbon dioxide. But he didn't have Geiger counters to measure
because this was a stable isotope. He had to develop a mass
spectrometer that measures the mass of atoms, so you could
distinguish carbon- 13 from carbon- 12, which are the natural carbon
isotopes .

Wood was one of these people raised on a farm for whom
building anything was not an impediment to doing what you wanted
to do. He built anything. He synthesized all his radioactive
compounds. He was a really remarkable guy, and he was a wonderful
person so that you were strongly attracted to him. What he
represented was an idea of what you would love to be like. That's
why most of the students adored him. In fact, I have a visit next
week from a man who is writing his biography.

We remained very close friends for many, many years. He
died about five, eight years ago. But he continued working into
his eighties. In the last decade of his life, he probably
published more papers than the rest of the department together.
It was amazing. We went to his seventieth birthday and his
eightieth birthday.

Hughes: You were using radioisotopes mainly, rather than stable isotopes?

Berg: Yes.

Hughes: And getting them from Oak Ridge?

Berg: Yes, you could buy them. You bought barium carbonate, which was
an insoluble compound. It's essentially a barium salt of
carbonate, BaC03. Organic chemists had worked out techniques that
converted barium carbonate to sodium bicarbonate, and then doing
organic chemistry to convert the sodium bicarbonate into organic
molecules. And we had to do all that.

Today, students just go to the catalogs and buy everything;
they make nothing. But we had to synthesize everything that we
made. And so a lot of times we had to learn the chemistry to make
methyl alcohol, how do you make propionic acid, or pyruvic acid,
or any of these molecules with a radioactive carbon atom in a

particular location in the molecule? These were fairly
complicated steps.

Hughes: Was that expertise in the department?

Berg: Yes, that was expertise that was largely in the department, and we
got lots of help. Sometimes you had to work out a procedure that
had not been done before. So you made your precursor molecules.
You either fed them to animals or injected them into animals or
incubated them with extracts. And then you recovered the
products, and then you had to determine if the product was
radioactive. That was easy. And then you had to ask where did
this radioactive atom end up in the molecule? So we had to
develop procedures for degrading molecules and recovering the
different pieces in a form where you could measure their
radioactivity. And then you could draw the chemical reactions
that must have intervened to convert this into that, if this
molecule ended up in that particular part of the other molecule.
And so we had to develop procedures for degrading molecules and
recovering the different pieces in a form where you could measure
their radioactivity.

Radioactivity made this kind of experimentation much simpler
than using stable isotopes. With stable isotopes, you had to have
this very elaborate mass spectrometer, and you had to recover
larger amounts of material. Whereas with radioactivity, you could
use literally trace quantities.

I remember very clearly once having to make methyl alcohol
from barium carbonate. I did this in a very large hood, with ten
millicuries of radioactivity, which was a very, very large amount
of radioactivity at that time. Today, people wouldn't think it
was very much. I set up this whole organic synthesis array, in
which the starting material was here, and the products had to go
through various kinds of bubblers and be collected in a reservoir.
I had to build the glassware myself. And when I did the
experiment, and I looked at the end, I had nothing. It turned out
that one of the glass bubblers had a pinhole in it, and all of the
gas had gone through the hole. I had lost ten millicuries of
carbon- 14, for which I was ridiculed and got a lot of flack. But
that was the trial and tribulation of learning. [laughter]

Visits by Arthur Kornberg and Herman Kalckar

Berg: I remember very clearly, Arthur Kornberg came to visit Western

Reserve University and gave a lecture. It was not long after he

had won the Paul-Lewis Award [1951] for his work in enzymes. This
would be about 1951 or '52. His picture had been on the cover of
Chemical and Engineering News. At that time, even small prizes
got you a lot of notoriety. Today, you win a prize, you might
earn a little paragraph in the back of the journal.

But anyway, when I read about Arthur, I discovered that he
was from Abraham Lincoln High School, grew up in Brooklyn, and so
on. And so after he gave his lecture, Harland Wood had a cocktail
party at his home for him, and I was invited, and he and I
chatted. We discovered that we were both from the same high
school and the same background. I asked him if there was a chance
that I could come work in his lab as a postdoc.

Hughes: You knew what research he was doing because you had gone to the
lecture?

Berg: Oh yes, not only his lecture but during graduate training we
studied every new paper that came out, and so I knew in great
detail what he had been doing. It was the kind of enzymology
which I had not had experience with, nor was there anybody in the
department at the time who did that kind of enzymology.

Hughes: Which was what?

Berg: Well, f ractionation, obtaining pure enzymes. We were content to

work with relatively crude preparations. Kornberg would turn over
in his grave if he knew any of his people ever worked with crude
extracts.

Hughes: Was he fairly unique at that time in insisting on working with
pure extracts?

Berg: Well, I think he was one of a small number. There were perhaps
half a dozen people who were really committed, and one of them
made the point, "Don't waste clean thoughts on dirty enzymes."
Kornberg had taken a sabbatical and gone to work with a man named
Carl Cori, who was one of the giants of biochemistry.

Berg: There were lots of other visitors, and one of them was a man who

was from Denmark; his name was Herman Kalckar. Herman Kalckar was
a brilliant scientist and had made major discoveries during the
late thirties, when he was a student in Copenhagen. And then he
came to this country on a Rockefeller fellowship. He went to
Caltech, and then the war broke out in 1939, and he was stuck in
the States. He remained at Caltech for a short time and wrote an
extremely influential review article, which gave him a lot of
notoriety. He then took a position at the Public Health Research
Institute in New York, and he spent the war years there. He

developed a whole new approach to being able to use enzymes in a
novel way.

Herman came and gave a seminar on that topic. I don't know
how many Danish people you know, but many of them are
unintelligible. He was more unintelligible than most. Their
language requires a lot of guttural sounds and throat sounds.
When Herman spoke English, he was very hard to understand, and he
had a flamboyant way of doing it that made it even more difficult.
So, nobody in the audience knew what he was talking about. But I
loved him; I thought he was great.

Hughes: Did you understand what he was saying?

Berg: I could see the outlines of what he had done, and it was

fascinating, because it looked like it was a new way of using
enzymology. What he was really developing was an analytical way
to follow enzyme reactions.

Hughes: But not with radioisotopes?

Berg: Not with isotopes. This was using a spectrophotometer. You get
spectral changes in certain molecules when the enzyme acts on
them, and therefore you can follow the reaction by following the
spectral changes. At that time there was a very new instrument
that had come out called the Beckman spectrophotometer. And the
Beckman spectrophotometer was one of the special instruments that
everybody sort of bowed around. And here Kalckar was using this
thing in this very clever way, and it just struck me. Besides, he
seemed like an interesting personality. When the war ended, he of
course went back to Copenhagen. So, I talked to him about the
possibility of going to work in his lab, and he said that was
fine.

Postdoctoral Positions

Deciding Not to Go to the Coris ' Lab

Berg: Meanwhile, Harland Wood had other plans for me. He had seen me as
one of his star students, and he felt that it was appropriate for
me to go on to Carl Cori's lab, and that it was a fitting place
for a bright young person to go and get the next level of his
training. Carl Cori was at Washington University in St. Louis,
and the stories I heard about St. Louis made it sound like it was
unlivable .

Hughes: The city itself?

Berg: Well, its location. It was known for temperatures in excess of a
hundred degrees Fahrenheit during the summer, maybe four or five
months of the year. And it was a southern city still. It was
relatively racist. I think blacks still had to sit in the back of
the bus at that time. It was very unappetizing. And so, I told
Harland Wood that I would not go to Cori's lab; I did not want to
live in St. Louis. He was greatly disappointed by anybody who
would turn down an opportunity to work with the great Carl Cori.

Hughes: You appreciated Cori's stature?

Berg: Oh, I knew Cori by name, and I had seen him at meetings. There

was no question that he and his wife, Gerty Cori, both of whom had
gotten the Nobel Prize, were sort of the top people in the field.
Arthur Kornberg had gone to do his apprenticeship there and came
to revere Carl Cori as well. So I lost a lot of stature with
Harland Wood by saying I wasn't going to work with Carl Cori. I
was going to work with Herman Kalckar in Copenhagen for a year
[1952-1953], and then I would spend a second year [1953-1954] with
Arthur Kornberg at the NIH. And that's what I did. So, we went
off to Copenhagen; I spent a year.

Postdoctoral Research Fellow with Arthur Kornberg,
Washington University, 1953-1954

Berg: During the time I was in Copenhagen, Arthur Kornberg was invited
to become the professor of microbiology at Washington University
in St. Louis. And so he wrote to me and said he hoped I still
planned to join him when he moved and took over this new
department. And I agreed to do it. So, I ended up in St. Louis
anyway . [ 1 aught e r ]

Hughes: Now, why did you agree the second time?

Berg: Because the prospect of working with Kornberg seemed much more

appealing than working with Cori. Cori was a great figure; Arthur
was a rising young star. And the kind of enzymology he was doing
was more appealing to me. He was much more aggressive in wanting
me to come than anything I had ever heard from Cori. Cori would
have taken me largely because Harland Wood would have said, "I
want you to take Paul Berg on." Whereas Arthur really wanted me
to come.

Arthur had gotten enough about me from other people. I kept
in touch with him when I was in Copenhagen, telling him about the
experiments we were doing. He was very much taken by the
discovery we made, and so he wanted me to come. Also he was
moving into a new venture. He had always had a sheltered life
being at the NIH, and here he was now taking an academic position.
He had the Job of creating a whole new department. I'm sure he
must have thought a little bit about what kinds of people he
wanted to recruit. At least he had a chance to have a look-see at
me as a postdoc. And as it turned out he eventually offered me a
position in the department.

Postdoctoral Research Fellow with Herman Kalckar, Institute of
Cytophysiology , Copenhagen, 1952-1953

Berg: Copenhagen was really great because working with Kalckar was great
fun. I learned to understand him, and if I didn't understand him,
I learned not to be embarrassed to just keep plugging away. What
I found was that the easiest way was to take him to a chalkboard
or blackboard, and we'd write what we had to communicate. If I
didn't understand him, we would try to draw the experiment. After
a while I got to be able not only to follow him, but almost to
anticipate the kinds of things he would be thinking about.

Hughes: I think of [Niels] Bohr-
Berg: Bohr was almost as unintelligible. In fact, I'll tell you a
little story. While I was in Copenhagen, Herman Kalckar was
invited to speak at the Danish Royal Academy of Sciences. He took
me and one of the other people in the lab along as his guests. It
was a rather spectacular Old World setting, with enormous
paintings on the wall of great figures in Scandinavian science.

There were two talks scheduled, followed by Danish
sandwiches and good beer. And the first speaker was an elderly
man. In fact, most of the members were extremely old. They all
had earphones, because most couldn't hear. I couldn't understand
the first speaker; he was speaking Danish. It turned out he was a
linguist, who gave a talk on some of the most erotic and
pornographic passages in Danish poetry. And so there was a lot of
snickering, and so on and so forth.

Hughes: You missed it all. [laughter]

Berg: And I missed it all. I was sitting, looking, and staring around
at the pictures. Then Kalckar got up, and he started to speak.

He was giving a scientific lecture about the research. And you
could see within three minutes, five minutes, the earphones came
off all these guys, and they sat back and just either slept or
whatever. [laughter]

Bohr, who was there, fell asleep. And when he did speak, he
was, at least to me, unintelligible. I gathered that even in
Danish, Kalckar was hard to understand. So when he was asked to
give lectures to the medical students, they didn't invite him back
again after he would give the first couple. He had an unusual way
of mumbling, which is not uncommon amongst Danes. And Bohr
mumbled also. Danes refer to their language as a throat disease,
not a language, plus this mumbling. It was just very hard. And
in English, it wasn't a heck of a lot easier.

Nevertheless, we had a great group in the lab. It was a
group from all over the world—from India, from Canada, from
Italy, and I forget where else, plus Danes, Swedes. It was a very
coherent, friendly group. It was an exciting period, because the
work that was going on in the lab was booming. It was one of
these things where a new discovery had opened up a whole new
world, and everything you did was new and successful.

Discovery of Nucleoside Diphosphokinase

Berg: I got involved in a project which very quickly turned out to be

hugely successful. An Australian postdoc Bill Joklik and I worked
together and published two or three papers on this one discovery
for one year's work.

Hughes: Did you come with an idea for a research project?

Berg: No. Kalckar had a physicist friend Thomas Rosenberg who dabbled
in biology and had some kind of cockeyed idea to explain a
particular reaction involving hexokinase. It's an enzyme that
converts glucose into a phosphorylated form of glucose, and it's a
very key step in the metabolism of sugars. It is normally viewed
as an irreversible reaction. It's a reaction between glucose and
ATP [adenosine triphosphate] which forms a compound called
glucose-6-phosphate and ADP [adenosine diphosphate] , and was not
known to be reversible.

He postulated that the reaction went in two steps; that an
intermediate, which was very, very reactive, immediately went on
to the product that everybody knew. This intermediate product, he
supposed, was a very special form of glucose phosphate, so-called

high energy, he called it. And so we talked about this
hypothesis; there was no evidence for it. This was a reaction
that Carl Cori had studied in great detail and had found evidence
that there might be a step that was influenced by insulin.

Rosenberg's idea was that insulin involved the second step
of this two-step reaction. So, I looked at it and listened. And
I said, "If that is true, one ought to be able to do the following
kind of experiment and show that you could transfer P32 from ATP
through this hypothetical intermediate to another molecule like
ATP, ITP. It was known ATP would not transfer phosphate to ITP.

So, Kalckar said, "That's an interesting idea. Why don't
you try and do that?" It was known that there was another form of
ATP, called ITP, which could react with glucose. So, I came to
the conclusion that if we took ATP with P32, and if we
phosphorylated glucose to this glucose metaphosphate, as we called
it, that glucose metaphosphate could transfer the P32 back to ATP,
but it could also transfer it to ITP. So, in other words, you
could transfer phosphate from ATP to ITP, but it would require
glucose .

So, we set up this experiment. We had to make our own
radioactive ATP. The idea was to put in radioactive ATP and study
whether the P32 transferred to ITP and required the presence of
glucose and the enzymes. Well, the experiment worked beautifully-
-P32 went from ATP to ITP like gangbusters, but it didn't require
glucose.

What we had discovered was a new reaction in which ATP can
transfer phosphate to molecules like ITP, and GTP, and CTP, and
UTP. It doesn't have anything to do with glucose; it doesn't have
anything to do with hexokinase. It was a wholly new enzyme. So,
just by setting up an experiment to test a particular hypothesis,
you test one kind of question and you find something completely
different, which is often true in science.

Making Radioactive ATP

Berg: There were companies that were making radioactive ATP, but dollars
were needed to pay, and Denmark didn't have dollars. So, we had
to make it ourselves. The traditional way of making P32-labelled
ATP was to inject a lot of P32 phosphate into a rabbit, exercise
the rabbit so that it breaks down all its muscle ATP, and then
allow the rabbit to recover and rebuild its ATP. Then you kill

the animal and you can dissect its muscles, and after a whole
series of extractions and a lot of complicated steps you get ATP.

We had an old bathtub up in the attic of the institute. And
so we decided we were going to inject this rabbit with about, I
don't know, twenty millicuries of P32, which was a lot. We put
this rabbit into the bathtub, expecting he was going to swim, but
he just sank to the bottom. We kept rescuing him and saying,
"Swim, you bastard." [laughter] We kept dunking this rabbit,
and he just wouldn't swim.

But eventually we got him out, and he was shivering. And we
figured that was enough. So we let him shiver for a while, and
then we wrapped him in a towel and put him near a radiator and
warmed him up for a while. Then we sacrificed him. Then we cut
him up and isolated all his muscle and eventually isolated a lot
of ATP. And that's what we used. It was such a funny story. I
tell that to students today, and they just can't imagine that
anybody ever made their own ATP.

Life in Denmark

Berg: So, things went extremely well in Copenhagen. We had a great

time. We met a lot of wonderful people. We traveled a lot, all
through Europe. We went skiing in Norway, visited Sweden,
traveled through Germany and Italy and the lakes region. It was
very inexpensive. I was living on a fellowship which paid $3,500
a year. We literally saved half of it. We had a villa in this
little fishing village outside of Copenhagen, and we saved enough
money to do all this travel.

In fact, Danish friends told us we were making more than the
King of Denmark, in terms of our income in dollars. And we ate
extremely well, even though Copenhagen was just emerging from the
effects of the Occupation. The war was over in 1946; in 1952,
there was still rationing when we got there. I remember going to
George Jensen's silver shop in the town, and everybody gathered
around the window looking, not at the silver bowl, but at the
peaches it held.

Berg: We couldn't buy certain kinds of food. Meat was rationed. By the
time we left, the rationing was just coming off. I remember we
didn't have a refrigerator in this little house; we had a little
door to the outside of the house so milk could be delivered. The

milkman would open the door, put the milk inside. It was open to

the outside temperatures; it kept things cooler. Eventually we

prevailed on the woman who owned the house to get us a small
refrigerator.

We loved living there. We lived in this village, which was
on the edge of this royal deer park. So when we had to walk to
the train, which took me into work every day, we walked along with
deer, and during the mating season you could hear this roaring.
It was incredible.

James D. Watson

Hughes: How common was it then for American graduate students to go
abroad?

Berg: It was just becoming both fashionable and possible, largely

because of the postdoctoral fellowship program that the NIH, the
American Cancer Society, a number of them had. Jim Watson, for
example, went to work with Herman Kalckar.

Hughes: Was that the same year?

Berg: Year before [1951]. When Jim went, Kalckar was not ever around.
Kalckar had a postdoc whose name was Barbara Wright, and he and
Barbara took up with each other. He left his wife, and he and
Barbara traveled all over Europe together. And so Jim never saw
Kalckar. He went to work with Kalckar to learn something about
enzymes. His advisor [Salvador] Luria said to him, "You ought to
learn some chemistry." And so Jim went there, but Kalckar wasn't
there. So, he moved to work with another man named Ole Maaloe who
was working at the State Serum Institute on bacteriophage. And to
this day, and on many, many occasions, Jim will talk about this
lost year in Copenhagen and about Kalckar.

I came the year after. By that time Kalckar and his wife
had separated, and he married Barbara. And so I got to know
Barbara. They had a child, which I guess was conceived well
before they were married. We had a great time together. So, for
me, that year was very successful. It was such a bad experience
for Watson that he left Maaloe after the year and went to
Cambridge.

Hughes: Just think how history would have been different if he had had a
successful year with Kalckar.

Berg: He might never have gone to Cambridge. In fact, Watson tells the
story that from Copenhagen he went to a meeting in Italy where
people were talking for the first time about DNA as the genetic
material. There was some preliminary structure work. And he got
all turned on about the need to solve the structure of DNA. He
left Copenhagen and got into terrible trouble with the American
Cancer Society, because they had given him the fellowship to work
in Kalckar's lab, and he didn't even notify them; he just moved to
Cambridge.

I remember Luria telling me that he had to write all these
letters to the American Cancer Society, trying to get them to
accept that Watson was a little bit bizarre and to forgive him.
But he was better off in Cambridge. And it was in Cambridge that
he and Francis [Crick] did that work on DNA structure.

Hughes: So, he went to Kalckar's lab not with DNA on his mind at all.

Berg: No, not at all. He wrote about that period in his book about the
discovery of the double helix.1

More on the Postdoc with Kornberg
Institutional Setting

Berg: After Copenhagen, I came back to St. Louis.
Hughes: Where Kornberg was already ensconced.2

Berg: He was already there. He got there in January 1953; we got there
in October. And the lab was very primitive. It had been an old
clinic; in fact it was a clinic building. The first floor was
where indigent people would be sitting or sprawled in chairs for
hours, waiting to see the doctor. There was this rickety elevator
that took you up to the fourth floor. And there was the
microbiology department, which literally had rooms with bare bulbs
hanging from the roof. It was just an amazing thing.

1 James D. Watson, The Double Helix: A Personal Account of the
Discovery of the Structure of DNA, New York: Signet Books, 1968.

2 For Kornberg1 s views on his time at Washington University, see his
oral history, cited on page 8.

Kornberg took this position because he really wanted to
leave the N1H. Cori had been a very strong force in persuading
him to come to Washington University. Besides, Washington
University was already well known; it was a place that had a
strong tradition in research. I think Kornberg must have been
promised a whole lot of support. [phone interruption]

Arthur tells the story that the then dean of the medical
school, a man named Oliver Lowry, who was a very well-known
pharmacologist, was head of the pharmacology department. He was a
tinkerer. He told Arthur that he would come up and personally
paint the labs so that they were presentable. He was going to
help with some of the wiring and fix up the place. He never did.
But he was that kind of a person anyway. It was so amusing.

When I got there, probably there were two or three labs that
were fixed up. One was the one that Arthur and his wife [Sylvy]
were working in, with a couple of postdoctoral fellows. Another
one was a very large lab which could probably have held six or
eight people, in which there was nobody working but had been fixed
up. Painted, lit, it looked presentable as a lab. And two other
labs, to which he brought people who had been postdoctoral fellows
at the NIH, and to whom he gave appointments as professors in the
new department.

Hughes: And who were they?

Berg: One was named Osamu Hayaishi, who went on to become one of the

leading biochemists in Japan and today in his eighties is probably
one of the most influential people in science in Japan. The other
was a man named Irving Lieberman, who eventually left never to be
heard of again. I don't know what ever happened to him. He was
extremely able in the lab, but kind of a weird guy. And the two
of them never got on very well, so he left.

When I came, Kornberg took me into this nice new lab and
said, "Here's where you're going to work." And I looked around at
this decrepit place. He was telling me, "Don't worry. We're
going to get it all fixed up." And we did over the years. I got
my Ph.D. in "52, went abroad for the year, came back from
Copenhagen in '53, and immediately we talked about what I might
work on. Kornberg gave me several suggestions of projects.

35
Lipmann and Lynen's Hypothesis

Berg: While I was in Copenhagen there had been a very significant paper
published from Fritz Lipmann1 s laboratory- -Lipmann was one of the
giants of biochemistry at the time—by a man by the name of Feodor
Lynen, who was a professor in Munich. I can't remember whether
Lipmann and Lynen had gotten the Nobel Prize by then, or they went
on to get it.1

Lipmann and Lynen and two of their students had published a
paper which provided a hypothesis or model for how a very key
reaction in metabolism worked. This was a reaction that was very
central [acetyl-CoA formation]; many, many people had been
studying it. It was a rather complicated reaction. Lipmann and
Lienen proposed a novel mechanism. A feature of the mechanism
that they proposed was that the first step was a reaction between
ATP and the enzyme, to knock off two phosphates from the ATP and
make an AMP enzyme complex. And then there was a second step in
which the AMP was transferred to coenzyme A, another one of the
components .

Berg's Research on Acyl Adenylates

Berg: I was intrigued by this notion of "an enzyme intermediate linked

with the enzyme AMP. And I was intrigued by it because although I
was interested in nucleic acids, I didn't really know anything
about them. But it seemed conceivable that this form of AMP was
an activated form that might be a precursor for building nucleic
acids. So I told Kornberg that what I wanted to do was work on
this enzyme-AMP complex.

Hughes: What was his reaction?
Berg: He said it was bunk.
Hughes: Why?

Berg: Because the hypothesis was based on a particular measurement they
made, which was to take ATP and incubate it with, quote, "an
enzyme," which was a very murky, crude enzyme, and show that the
two terminal phosphates would exchange with free radioactive
pyrophosphate in the medium. If ATP reacted with the enzyme, you

Lipmann received the Nobel Prize in 1953.

would liberate inorganic pyrophosphate and produce a complex of
the enzyme with adenosine monophosphate (AMP). Since they
supposed this was a reversible reaction, one would anticipate that
radioactive POP in the medium would react with the enzyme-AMP
complex to reform ATP which would be radioactively labelled. And
that's what Lippmann and Lynen found.

Kornberg had already studied several reactions where ATP
exchanged its two terminal phosphates with radioactively labelled
pyrophosphate. But his reaction did not occur by making an
enzyme-AMP complex, but by another, more conventional, mechanism.
So he said, "I don't believe any of it." I said okay, that may
be, but I'm going to take a shot at it anyway. I'm going to
purify the enzyme to see if it can produce the enzyme AMP, and to
characterize it.

Hughes: Was your enzymology pretty good at this point?

Berg: Yes, by that time, I think I knew how to purify an enzyme. I had
been doing it in Copenhagen; that was the thing to do. We had
discovered a new reaction, isolated the enzyme, purified it to
purity, and characterized that system. So, Kornberg said, "Okay,
if you want to do it, go ahead."

Hughes: Did he agree somewhat because you had proven yourself?

Berg: Perhaps. Kornberg had a history of directing the work of people

in his lab. He more or less dictated what people did. So, it was
unusual that he allowed me to do what I wanted to do. It was not
central to what was going on in the lab. But from his estimate of
my ability or reputation, he let me do it, even though he
predicted it was going to be a waste. And I said, "Well, we'll
find out if it's wrong. Because when I purify the enzyme, we're
either going to prove that this is true or it's not true." So, as
long as I was willing to approach it from the point of view of
purifying the enzyme, that was okay.

The reaction I'm referring to was:

ATP + acetate + coA <-> acetyl coA + AMP + PPt

Lipmann and Lynen proposed that the reaction occurred in
three steps:

ATP - Enzyme <-> AMP-enzyme + PPt
AMP-enzyme + coA <-> Enzyme-coA + AMP
Enzyme-coA + acetate <-> acetyl coA + AMP

The novel feature was the creation of enzyme-AMP and enzyme
coA. The evidence for their proposal was that radioactive PPt was

quickly incorporated into the two terminal phosphates of ATP with
the enzyme alone, none of the other substrates.

So, I started off, and very quickly I found that, as I
purified the enzyme, there was no longer any exchange of
pyrophosphate with ATP, even though the enzyme was capable of
catalyzing the overall reaction. I began to ask, "How could
Lipmann and Lynen have possibly gotten those results?" These were
two very, very distinguished scientists who put their name on a
paper that was offering this hypothesis.

And so I began to ask, "Well, what if I tried to carry out
this reaction not in totality, but just parts of it?" In other
words, I'd leave out one of the substrates so the reaction could
not go all the way. And what I discovered is that when I added
acetate, one of the other substrates, to the mixture of ATP,
pyrophosphate, and the enzyme, it reconstituted the exchange
reaction. That indicated that acetate was needed in addition to
the enzyme to promote the exchange. Clearly, Lipmann and Lynen
were wrong!

My observations indicated that the enzyme catalyzed a
reaction between ATP and acetate to form acetyl-AMP.

ATP + acetate <-> acetyl AMP + PPj
That would make the subsequent reaction:

acetyl-AMP + coA <-> acetyl-coA + AMP

You see that these two steps produce the known products but
not by the three steps proposed by Lipmann and Lynen.

Hughes: How do you work out a previously unknown molecule?

Berg: One clue was the existence of a somewhat similar compound called
acetyl phosphate--m-acetyl adenylate. The most likely structure
was that acetate was linked to the phosphate of AMP. It then
required that we prove the existence of acetyl-AMP and show that
it behaved in the subsequent reaction as indicated.

So the question is, how do you prove the model? I went to
the chemistry department and talked to one of the people there and
said, "If I wanted to make something called acetyl AMP, how would
I do it?" People knew how to make acetyl phosphate. You just
took acetyl chloride and mixed it with silver phosphate, and lo
and behold, you got acetyl phosphate. So, I said, "Well, I'm
going to take silver adenylate and acetyl chloride, and I'm going
to mix them. And I did. And I got an unholy mixture-mess. But
out of it I purified something which when I added it to this
onzyme, plus pyrophosphate, gave massive amounts of ATP.

Then, working out the rest of the reaction was pretty
simple. Kornberg was always there saying, "Wow, great," and so
on. And then there was a national meeting, the Federation [for
Experimental Biology] meetings, in 1955, I guess it was. I went
to that meeting, and the word got around of what I had done. So,
I was invited to give a special presentation, which I did. And it
blew everybody away, including both Lipmann and Lynen, who were
there.

Hughes: What reaction did they have?

Berg: Embarrassment. Sort of a mixture of admiration and embarrassment.
Lipmann told me he could never live down, in his own mind, having
made such a stupid mistake. As it turned out, they had taken a
concentrated extract of yeast, which was like mud, and because
they had grown the yeast on acetic acid, it was not surprising
that their extract contained some acetic acid, which was all you
needed to trigger that reaction.

Lynen, in his more sober moments, told me it was the only
time that anybody had shown him to be wrong. And so for me it was
kind of a big high, because here 1 was a postdoc and had come on
to solve the mechanism of an important biologic reaction and
triumphed over Lipmann and Lynen. This turned out to be a very
general reaction, because all fatty acids are activated this way.
This was the first step in the process by which you build up long-
chain fatty acids.

Rising Star

Berg: So, there I was in a pretty early stage of my career already with
two big hits. And in publishing this work--I think there were
about three papers--Kornberg did not put his name on them, which I
think was a first and last. I don't know of any other paper or
work that has come out under his tutelage on which he did not put
his name. By his not putting his name on it, I got the full
glory. Had his name been on them, there's no question, I would
not have profited and benefitted from the discovery in the same
way because, as is often the case, the senior author gets a lot of
the credit for it. And the people who did the work, who actually
had the insight, or who even came up with the idea, get second
billing. I have always been extraordinarily grateful to him for
doing that.

I don't know whether Kornberg understood that, or whether he
just felt he had not suggested that problem to me. I had insisted

on giving it a try. While he was there for me to talk to all the
time, and was always available for me to bounce ideas—why I
couldn't get this to work or that- -he in the end felt it was my
work. There was a series of papers. I eventually described the
synthesis of this previously unknown compound and worked out the
structure.

So by the time I got to this stage, which was 1955, I was
pretty well-known in the field. And Kornberg had already asked me
to stay on in the department. Even though he didn't have a
faculty appointment for me, the school put me up for a Scholar in
Cancer Research appointment. It was a special fellowship which
was to provide a three-year appointment, with the understanding
that the university would give you an academic appointment at the
first opening. But you would be in this interim position. It's
like the Markey Fellowship, which serves to bridge the period
between completing a postdoc and having the first faculty
appointment .

Hughes: [Shows Berg his curriculum vitae].

Berg: Yes, "Scholar in Cancer Research, American Cancer Society." It
was for 1955, and then in '56, at the first opening, I was
appointed assistant professor.

Hughes: So you worked independently at a much earlier stage than is usual.

Berg: Yes, even in graduate school, nobody had assigned a problem to me
for my Ph.D. thesis, which is usually the way things work. But I
had suggested an idea of how to solve a particular problem, so
that was a kind of early independence. Even though you're never
really totally independent; you get a lot of feedback from people
all the time.

When I went to Copenhagen, I had suggested trying to test
Rosenberg's hypothesis in a way that, as many experiments do,
leads you into something that was totally unexpected. And then
coming to Kornberg with a preconceived notion about what I wanted
to work on, which was different from what was going on in the lab
and from what he had suggested I might do. And then this work led
on to the discovery that a similar kind of reaction happens with
amino acids, and that the first reaction in the assembly of
proteins is to modify amino acids by their attachment to AMP and
then be able to attach them to RNA molecules and allow them to be
assembled into proteins. The discovery of this form of
activation, as it was called, turned out to have great general
applicability and significance. And so, it was seen as sort of a
major discovery.

Kornberg's Background

Hughes: Not only was Kornberg an M.D. rather than a Ph.D., but he also had
never had formal training in biochemistry. Was that a
consideration in terms of your working with him?

Berg: No, not at all.

Hughes: You looked at what he had achieved.

Berg: Oh, yes. First of all, many European scientists, [Severo] Ochoa
and Cori, they were all M.D. -trained. In Europe, it was
traditional that if you wanted to research in the biological area,
you got an M.D. training. With Kornberg, I don't remember that I
even thought one second about it, although all the people that I
had been affiliated with as a graduate student were always
straight Ph.D.s. I don't remember that it ever occurred to me to
wonder. In fact, almost all the work Kornberg did was only
tangentially related to medicine.

As a medical student, he did research in his own spare time,
and the experiments he did were almost always sort of biochemical
in nature. He became interested in nutrition. He finished his
medical training, and he went into the coast guard, and he was
assigned to a ship. He probably told you the experience of trying
to take a crew man's tonsil out. They were out at sea, and this
guy was in terrible agony with this inflamed tonsil, and Kornberg
was the only physician on board. So he went in and excised this
guy's tonsil, only he was not anesthetized. That experience
taught him that medicine was not what he wanted to do, and so he
got transferred to the Commissioned Corps of the NIH [National
Institutes of Health], while he was actually in military service.
When he left the Public Health Service, he was a commander, or
something, in the navy rank.

When he went to the NIH, he started working on nutrition.
II

Berg: So, as Arthur says, he realized that there's all this happening
within the animal, and you can't tell what's going on. So, he
decided enzymes were something that he had to learn about. He
went to work with Cori and then with Ochoa. Ochoa was a real
enzymologist. And I think Arthur learned a lot of enzymology
during those two stays, particularly since there were graduate
students and postdocs in the lab, and he mixed with them. When he
went back to the NIH, he was finished with nutrition. And I don't
know if it was immediately after that he became the head of the

laboratory [Chief of Enzyme and Metabolism Section, National
Institute of Arthritis and Metabolic Diseases] . Soon after, there
were, in succession, spectacular discoveries of new reactions,
purified enzymes, nailing down the mechanism of the reaction-- just
one after another. That's when [1951] he got this Paul-Lewis
Award in Enzyme Chemistry for the enzyme work.

I also recognized myself that enzymes were in the end the
only level at which we could understand the biochemistry, so just
starting out, we realized we had to get some training and
experience with enzymes. Kalckar was doing enzymology, purifying
enzymes, measuring them spectrophotometrically. Arthur was
purifying enzymes. They were both identified as rising stars.
And so an ambitious young guy is going to definitely go to the
place where the action is.

Hughes: And that's what the ambitious young guy did. [laughter]

III RESEARCH INTERESTS: NEW AND CONTINUING
[Interview 2: August 12, 1997] ##

Research on Fatty Acid Activation

Returning to a Curious Reaction

Hughes: Dr. Berg, last time we were talking about St. Louis, and you have
more to say about the research that you did there.

Berg: The work concerned how acetic acid is activated for its ultimate
incorporation into long-chain fatty acids. The mechanism was
novel and had not been seen before. Now, in the course of
purifying the enzyme that carried out the formation of acetyl CoA,
I had come across another reaction, which clearly was not that
system, but which had the same characteristics. Namely, it
catalyzed the exchange of inorganic pyrophosphate with ATP, but
instead of acetate being the promoter of this reaction, it was an
amino acid, methionine.

That was curious. It wasn't at all clear why methionine
should be involved in promoting a reaction like fatty acid
activation. I put that on the shelf and waited until I completely
clarified the fatty acid system. And when that was done, I went
back to this reaction with the amino acid, and for the life of me,
I couldn't figure it out. This was a reaction with no net charge.
With only ATP, the amino acid methionine, and radioactive
pyrophosphate, the pyrophosphate would exchange with ATP very
rapidly. Nothing would happen in the absence of methionine.

Some reaction was occurring between ATP and methionine that
was causing the release of pyrophosphate, and that reaction was
reversible, so you could reincorporate pyrophosphate back into
ATP. Well, I had studied the fatty acid system, which had exactly
the same characteristics, namely in that case the enzyme uses

acetate to promote the exchange of ATP and pyrophosphate. Now the
acetate system has another component to it, which is coenzyme A,
and coenzyme A acts as an acceptor of the activated acetate. The
entire reaction involves first the reaction between ATP and
acetate to activate, and then to transfer the activated acid to
acetyl CoA. So I reckoned that the amino acid system must be very
similar, that what we were doing was activating the amino acid to
some form, and there had to be an acceptor. But there was no
known acceptor. So the question was, why don't we try to find out
what the acceptor is? We could easily devise an assay that if you
had the acceptor the reaction would go all the way, instead of
just going back and forth.

James Ofengand's Research on an Acceptor

Berg: The first graduate student I had, a fellow named James Ofengand,
arrived and he was put on that problem. I guess it would have
been 1955, because he finished in four years and left when we
moved to Stanford. So Jim started to try to identify something
which can act as an acceptor of this activated amino acid. Sure
enough, he fractionated crude materials and found something which
did in fact act as an acceptor. And when he ultimately purified
it, it turned out to be a small RNA molecule, which subsequently
was called transfer RNA [tRNA]. And so the reaction was
completely parallel to the fatty acid system. Only in this case
an amino acid was being activated. It turned out that the amino
acid was activated through its carboxyl group, just as the fatty
acid was. When it's activated through its carboxyl group, the
amino acid is very, very efficiently transferred to the tRNA. The
interest was that it looked like it might be involved as one of
the intermediates in the assembly of proteins.

Paul Zamecnik's Research on Amino Acid Incorporation In
Vitro

Berg: There were indications from other laboratories that amino acids

had to interact with RNA before being incorporated into proteins.
Paul Zamecnik at Harvard and Mahlon Hoagland, who was
collaborating with him, had been able to show that amino acids
could be incorporated into proteins in vitro, and that a molecule
which they called soluble RNA was required. It turned out the
soluble RNA was the same as transfer RNA [tRNA]. So, they showed

there was an RNA requirement for incorporating amino acids into
proteins.

Purifying Enzymes Activating Some Amino Acids

Berg: We found that the amino acids were being attached to this tRNA,

and we reckoned that the amino acid-tRNA was the precursor or the
donor of the amino acid for the assembly of protein chains.

Hughes: What year was this?

Berg: This was 1956; it could be '57, somewhere in that period. And I
think our first published works on the activation of amino acids
is in that period. Subsequently, we went on to show that if you
looked back in crude extracts, you found that there were enzymes
to activate different amino acids. By the time we came here
[1959], we had purified the enzymes that were necessary for
activating some six or seven amino acids, each enzyme being
specific for a single amino acid, and each being specific for a
separate tRNA molecule.

It was our work that really established this notion of one
tRNA per amino acid. You could see that there were twenty
different enzymes; each one of them could recognize one of the
twenty amino acids to the exclusion of the nineteen others, and in
the presence of ATP activated that amino acid, and then
transferred it to its acceptor tRNA.

Hughes: It sounds as though you were not provoked by Watson and Crick and
the central dogma: DNA, to RNA, to protein. You came across this
by a strictly biochemical route.

Berg: Oh, yes. The central dogma at that time was, DNA is responsible
for encoding proteins. But the "DNA to RNA" wasn't even known.
There was a presumption that RNA was involved, but actually there
was a misconception. It was thought that the RNA that was
involved was in the ribosomes. The ribosomes are the machines on
which the proteins are assembled. But in point of fact, it isn't
the RNA in the ribosomes which is important; it's the so-called
messenger RNA. And the messenger RNA hypothesis wasn't made until
1959. So, we were just following our nose and saying, how do you
assemble proteins?

The Zamecnik group was the first one to create an in vitro
system that showed that if you put in radioactive amino acids,
they could end up in proteins. If you were a biochemist you would

say, "Now, let's fractionate this system and ask what are the
important elements for that reaction?"

We came at it quite from the back road. We weren't
interested in protein synthesis. We were fresh out of finding the
mechanism for activating fatty acids and stumbled, if you will, on
the fact that a similar kind of system was necessary for
activating amino acids. And once we recognized that enzymes were
putting amino acids on tRNA, and knowing of the Zamecnik work, we
were in up to our ears in protein synthesis at that point. So
then the question to ask is, attaching an amino acid to a tRNA,
and each amino acid to a different tRNA, how are all of those
amino acetyl tRNAs, as they're called, used in protein synthesis?

Mike Chamberlain and Bill Wood

Berg: When I came here in 1959, I had two superb students. One was Mike
Chamberlain, who's a professor at Berkeley, and Bill Wood, who
came from Harvard; both of them came as Harvard undergraduates and
joined the lab. Bill Wood is a professor at Colorado, in Boulder.

What Bill did was to set up an in vitro protein synthesis
system in our lab. He purified ribosomes, and he prepared a
fraction which contained all of these enzymes and all of these
tRNAs, and demonstrated that the amino acetyl tRNAs were in fact
the precursor for incorporating amino acids into protein. Mike
Chamberlain was one of the very first people to purify RNA
polymerase, because now we knew that there was a messenger RNA.
The messenger RNA must have been made off the DNA.

So what was the enzyme responsible for making messenger RNA?
Mike Chamberlain, starting with crude extract of E. coli, detected
an activity of converting ATP, UTP, GTP, and CTP into RNA, and he
began to purify that. He was probably one of the first to have
actually published a procedure for getting purified RNA
polymerase, and he did a lot of characterization.

So, we had in the lab then, after we moved here, the
expertise for two parts of the system for gene expression. One
was transcription, and the other one was translation.
Transcription generates the messenger RNA; translation is the
mechanism for converting that messenger RNA sequence into a
protein sequence.

Arthur Kornberg's Research on DNA Replication
Research on DNA Synthesis

Hughes: If you include Arthur in that picture, you have his work on the
very beginning of this process.

Berg: On DNA replication.

Hughes: Arthur arrived at the DNA synthesis problem circuitously as well.1
His original interest was not specifically in nucleic acid
synthesis, as I understand. And you just told me that you arrived
at the problem of protein synthesis by a circular route.

Berg: I think ours was probably more accidental than his. He has

written that, whether you take it at face value or not—it differs
among different people. He says, "The fact that Watson and Crick
identified DNA as the genetic material had no bearing on my choice
to work on DNA. I worked on DNA because it was an interesting
biochemical problem, and I couldn't have cared less if it was the
genetic material."2 I've wondered whether that was a bit
disingenuous, but he holds to that.

But it was very clear: when he was working on nucleotide
synthesis, he says that he already had in mind that the long-term
goal, if you think the way he does, was how will these nucleotides
assemble into nucleic acids? So, in St. Louis, he was working on
nucleotide synthesis—how you convert purines and pyrimidines into
triphosphates . Already in St. Louis, and I think it must have
been something like 1957, '58, he began to ask, "Now, if I can
make radioactively labelled nucleoside triphosphates, can I find a
system that will actually polymerize them into DNA?

And so, the DNA synthesis story actually starts in St.
Louis, and as he has described in his book, it's a really an
extraordinary story, because it shows how a person who is
determined will persist and believe what most people would not
have believed. In his initial experiments, the amount of
radioisotope incorporation into DNA he got was so small that it
was barely above the radiation background. Many people would have
ignored that. He maintained that the fifty counts above

p. 8.

1 See Arthur Kornberg's oral history, cited p. 8.

2 Dr. Kornberg made a similar statement in his oral history, cited

Hughes:

Berg:

Hughes:
Berg:

Hughes :
Berg:

Hughes ;
Berg:

background of radioactive material had the characteristics of DNA.
He could subject them to various kinds of chemical tests and was
convinced that the material he was making in his cell-free system
had the characteristics of DNA, so he pursued it. He already was
onto DNA replication before we left St. Louis.

He could have that confidence because he was so sure of his
technique? I mean, the fact that he insisted on working with
clean enzymes?

Well, he didn't have clean enzymes,
in extracts.

Then why was he so confident?

Those experiments were done

Well, you do good controls, and you subject your findings to the
most rigorous tests. By tests, what I mean is you ask: if it's
DNA, it should behave like this. If it's not DNA, it can't
satisfy all these criteria. So, you get a little bit of a
reaction, and you put this fairly intensive scrutiny on it. And
if it behaves like DNA, you go ahead. And that's what he did. In
fact, when he tried to publish the work, it was turned down. He
had one heck of a time getting the work published.

Why?

I'm not sure, actually. My recollection is that it was turned
down in large part because calling it DNA, without showing it had
genetic properties, was sort of an extrapolation. While he had
something that behaved chemically like DNA, DNA is supposed to be
the genetic material, and he didn't have a test for the genetic
activity of what he had made. So, in fact the paper kept being
turned down. Eventually, it was published. But the point I
wanted to make was, he was already on the track to try and learn
something about DNA synthesis.

That's another reason why he would pay attention to a finding that
was barely above background.

Yes, that's right. He reasoned that if thymidine was being
incorporated into DNA, it had to be converted to something else
before it could be incorporated. He suspected that the true
precursor must be thymidine triphosphate. So, he set out to
chemically synthesize thymidine triphosphate.

And then, of course, the incorporation went much better.
The levels were now much more respectable. He had a good assay.
He could begin to purify the enzyme that was incorporating
thymidine triphosphate. As soon as he began to do a few

purifications, he showed it required the other three precursors of
DNA (d[deoxy]ATP, dCTP and dGTP). In crude extracts, they're
usually there in trace amounts. You can't show that they're
required, because you're getting a very small amount anyway. But
once you purify a little bit, you now find that thymidine
triphosphate by itself is not incorporated; you need all the
others. That gives you more confidence that what you're making is
in fact DNA.

Hughes: Yes, I see.

Berg: So, it's kind of the dogged biochemical approach, and I think the
faith--and it is faith--that you can produce in vitro what must
happen in the cell, and that you have to purify it to eventually
be able to uncover the mechanism.

Nearest Neighbor Experiment

Berg: Actually, before we left St. Louis, Arthur had already established
the parameters of that DNA system, to which many people refer even
today. He was able to show, in what he called the nearest
neighbor experiment, that the frequency with which a nucleotide
goes in next to another nulceotide is exactly the same as [the
frequency] at which it occurs in the DNA used as a template. And
he proved some important points about DNA replication: that it had
to be, what we called, anti-parallel synthesis, which was not
proven by the Watson and Crick structure.

DNA as the Genetic Material

Hughes: In the paper that he had trouble publishing, did he show that the
four bases were necessary?

Berg: I think so.

Hughes: And that still was too much of a leap of faith to say, this is
DNA; this is the genetic material.

Berg: Right. I don't remember that the issue was whether somebody would
believe that DNA was the genetic material. In fact, it was the
other way around. It almost was that the true nonbelievers were
the people who said, "Well, DNA has a property; it's the genetic
material; it confers genetic specificity. How do we know that

what you've made is DNA? It was actually 1967 before he actually
showed that he could make a viral genome.

Despite his statement that he didn't care if [DNA] was the
genetic material or not, he clearly tried at various stages to
determine whether the material they were making did have some
genetic property. They tried to make transforming principle, but
that didn't work. He accepted that DNA was the genetic material,
and he was now making it in a test tube. The ultimate thing would
have been to prove that what he made in the test tube had
biological activity. Although, in the beginning I'm quite sure
that wasn't the motivation.

So, Arthur's getting into DNA replication was less
accidental than our getting into protein synthesis, which was
purely a result of the fact that we had stumbled onto a reaction
which resembled one which we had been working on. What got us
into protein synthesis was that the reaction we found looked like
it was producing the precursor to protein synthesis,
[interruption]

More on Amino Acid Assembly and Messenger RNA Research

Berg: We worked on that for quite some time. Being the biochemist that
I was trained to be, and under Kornberg's tutelage and
encouragement, I was pretty much a classical biochemist in his
mold: you find a reaction, you purify the system, and you work out
the mechanism using pure enzymes. So what happened for probably
five or six years after we moved here was to work out this whole
system of how amino acids become activated for protein synthesis
and the mechanism by which the amino acids actually become
assembled into a polypeptide chain. And, in addition, how you
make the messenger RNA that actually directs the order of
assembly. So those were really the major activities going on,
purifying all of these so-called amino acyl tRNA synthetases. As
I say, there are twenty different ones.

You might have thought the simplest scheme would be twenty
different tRNA's, each one accepting only one amino acid. As it
turned out, there are probably closer to a hundred different
tRNA's, and for any one amino acid there are probably two, three,
or four different tRNA's. We came to understand why that was
necessary. The genetic code has sixty-four triplets, sixty-one of
which actually specify amino acids. That means that the code is
degenerate, meaning there are more codons — triplets — for each

amino acid than just one-to-one. And if you have different
triplets than you have to have different tRNA's.

What we studied for some time was, how does the amino acid
activating enzyme recognize one amino acid to the exclusion of the
nineteen others? Because all the amino acids have a common core;
they have a carboxyl group and they have an amino group, and all
the amino acids look the same. The only thing that's different is
that they carry side chains which are of different kinds. And
that means that each enzyme has to distinguish each amino acid on
the basis of its side chain.

Some of the amino acids are very similar. It seemed
reasonable to ask how could one enzyme distinguish between the
amino acids isoleucine and valine, which differ ever so slightly.
You would imagine that if an enzyme could recognize isoleucine, it
must also be able to recognize valine. We discovered that in fact
the enzyme does just that; it makes mistakes. But it has an
extraordinary capacity to rectify its mistakes, because once it
transfers a wrong amino acid onto a tRNA, it knows it has made a
mistake, and it clips it off. So, you never get the wrong amino
acid going into a particular position on a protein. We worked out
a lot of the details of that specificity.

The second part of the specificity: once the enzyme has made
a particular amino acyl AMP [adenosine monophosphate] , which is
the intermediate, how does it recognize the correct set of tRNAs
to the exclusion of the hundred others? All the tRNA's look very
much alike. They're all small; they have between seventy and
ninety nucleotides; they're all folded in essentially the same
way. And yet the protein seems to be able to recognize some small
subset, puts the amino acid on those, and doesn't ever put it on
the wrong ones. So, we worked out a lot of the basis for that
specificity, new assays and so on and so forth.

Hughes: Is it a somewhat unique situation in biochemistry that enzymes are
forced to be so discriminating?

Berg: This is probably one of the most discriminating of all. You could
say polymerase is almost the other extreme: it uses any one of the
four triphosphates. And they differ. I mean, ATP, CTP, and UTP
all look very different, yet the enzyme knows how to use each one
of them, but dictates which goes in first or next; the order is
determined by the template. The enzyme is just there to match
whatever it picks up. If it doesn't match, it's released. At
random it picks the triphosphates; if they form a hydrogen bond,
it will make the linkage.

But in the case of amino acids, activation is very highly
specific. Once the amino acid is attached to the tRNA, its fate
is sealed. It will go into a position in the protein dictated by
the tRNA, not the amino acid. The amino acid could be anything.
Seymour Benzer demonstrated in a brilliant experiment that if you
put an amino acid on a particular tRNA, and then chemically change
the amino acid (cysteine into serine), it goes into the protein in
position calling for cysteine, not serine.

Berg: Thus producing the correct sequence in the protein is determined

by the specificity of these activating enzymes. If the activating
enzymes make mistakes, then the protein will be incorrect. That's
why we focused so much on trying to understand the nature of the
specificity and the error-correcting features that the system has.
So between 1959 and roughly 1965- '66, we focused on understanding
both transcription—the copying of DNA into RNA--and the assembly
of amino acids into proteins, specifically on this activation
step.

Gene Regulation

Pasteur Institute Contributions

Berg: Meanwhile, of course, a lot was happening working out the holy
trinity, which is DNA to RNA to protein. The Paris group at
Pasteur pioneered in the field of gene regulation. How do you
regulate whether a gene is transcribed or not?

It was known for quite a long time that in normally growing
E. coli, for example, most of its genes were not working. They're
only expressed when the cell needs them. The induced enzymes are
enzymes which are not expressed at all unless the cell senses a
need to make those enzymes in order to metabolize some material in
the medium. Scientists at Pasteur worked out a whole lot of the
details of this control mechanism, involving so-called operators
and repressers and so on.

Hughes: You had people in your group in St. Louis who had been at the
Pasteur Institute.

Berg: Melvin Cohn, David Hogness.
Hughes: Yes, and Dale Kaiser?

Berg: Dale Kaiser worked on bacteriophage . He had been to Pasteur, and
he worked with [Andre] Lwoff on a particular aspect of
bacteriophage lambda.

Stanford Biochemistry Contributions

Hughes: The idea of gene regulation was already in the wind before you
arrived in St. Louis?

Berg: Dave Hogness and Mel Cohn had worked on that in the late fifties
and had done one of the classic experiments, which showed that
enzyme induction actually involved totally new protein synthesis
rather than activation of an inactive form of the bacterial
enzyme, and induction is nothing more than conversion of an
inactive form to an active form. They showed that when the
inducer is present, the cell begins to make proteins de novo, i.e.
from scratch. And that proved that induction was really control
of protein assembly.

Using genetic tools primarily, [Jacques] Monod and
[Francois] Jacob showed that there must be a region upstream of
the beta-galactosidase gene which regulates that gene's expression
and that there was a represser that binds to that regulatory
region blocking gene expression. Thus, when the represser is
bound to that region of the DNA, beta-galactosidase is not made.
In this case, the inducer binds to the represser causing it to
come off the DNA, allowing expression of the gene to go on. The
details were worked out I'd say in the late fifties to early
sixties when Monod and Jacob and their colleagues did their famous
work identifying the operator (the control region) and the operon
(groups of genes that are regulated together).

We were following that work closely because Mel Cohn who had
worked with Monod was in our department, and he was educating us.
Most of us were biochemists; we were not geneticists, and we were
not microbiologists, but Mel Cohn was both. And so we were
learning about what was going on in Pasteur through him. In
fact, Monod and Jacob came many times to St. Louis and we got to
know them. We became friends with them as well as discussing
their research with them.

Dale Raiser and Bacteriophage Lambda

Berg: My best recollection is that sometime in 1965 Dale Kaiser gave a
graduate course on bacteriophage lambda. He was really already
one of the experts in this field. And he was a wonderful
lecturer. The last lecture of his course attempted to draw the
analogy between bacteriophage lambda and a mammalian tumor virus.

Now bacteriophage lambda, just to give you a little
background, is a virus which has two possible outcomes when it
infects E. coli. One is, the virus multiplies and the cell dies.
It pops open and releases several hundred bacteriophage particles,
They go on to infect other cells, those cells lyse, and you
produce what's called the lytic phase of bacteriophage lambda
infections. That's the way most bacteriophages work. They kill
the cells in which they multiply.

But what had been discovered in the Pasteur Institute by
Andre Lwoff , with whom Dale Kaiser had worked, was that
bacteriophage lambda frequently enters the chromosome of the
bacterium and remains dormant. The bacterium continues to
multiply perfectly normally, but it has acquired a new set of
genetic information, that carried by the bacteriophage genome.
But a complicated system keeps most of the genes of the
bacteriophage repressed, and so the bacteriophage genome is
maintained in the bacterial genome. But with a very, very low
frequency, the virus genes are spontaneously activated and the
virus begins to multiply and kill the cells. The phenomenon is
called lysogeny.

Dale Kaiser was one of the experts of this phenomenon, and
that's what he had studied. Cells that are lysogenic cannot be
infected, because they're producing a represser which is keeping
all viral genes repressed. So when a new virus chromosome comes
in, the represser blocks the action of its genes, and new
infections don't work. Dale had studied this phenomenon called
immunity. He was a terrific colleague. He was bright. He
brought a whole new world to most of us .

54
Research on Tumor Viruses

Turning to Tumor Viruses as an Experimental System

Berg: Now, it was already known that there is a system of mammalian

viruses which infect cells, integrate their chromosomes into the
chromosomes of the cell, and the cell doesn't die. In fact, the
cell becomes transformed into a tumor cell. That's why these
viruses are called tumor viruses. They rarely cause lysis; they
rarely kill the cell.

SV40 and polyoma are two viruses that are characteristic of
this group. They are small DNA viruses. When they infect cells,
depending upon the type of cells, they either kill the cells and
produce more virus particles, or they integrate into the
chromosome and remain dormant. In the latter case, they confer a
new property on that cell, namely it becomes a tumor cell. When
Dale contrasted these two systems, lysogeny with bacteriophage and
oncogenesis or tumorogenesis by tumor viruses, he pointed out the
striking similarities.

Hughes: That was a novel comparison at the time?

Berg: No, I think people who had been working with the tumor viruses

already were aware of lysogeny and were thinking that that might
be a compatible system. But it turned out not to be the same
because in the bacteriophage a represser is produced which blocks
gene expression in the viral genome. In the case of the mammalian
cells, there is no represser; the virus DNA integrates into the
chromosome and becomes stably associated with the host
chromosomes. The virus genome can't replicate itself. But it
continues to express some of its genes, one or more of which is
necessary to convert the infected cell into a tumor cell. So,
these tumor viruses carry a gene which causes cancer. As long as
a cell retains that virus gene, it grows in an aberrant way. I
was intrigued by that. I was getting a little bit tired of
working with bacteria.

I should step back for a moment. The studies with the
mammalian viruses are done in tissue culture. Just as in the
bacterial system you grow E. coli on a petri plate and you infect
them with a virus, you grow mammalian cells on a petri plate and
you infect them with a virus, then you can identify cells that
become transformed. I was also well aware that we had learned an
enormous amount about molecular biology, gene function,
regulation, etcetera, by studying the viruses that infect
bacteria.

There were two approaches to exploring molecular biology.
One was to study the bacterial cell, and the other one was to
study what happens after you infect the bacterial cell with a
virus. If you think about it, when you infect the cells a new set
of genetic information is brought into the cells. Now you have
almost a synchronized system; all the cells are infected, and now
the virus's genetic program takes over. So if you want to study
gene regulation, you could study the regulation of the
bacteriophage's genes, rather than the more complicated ones of
the cell. The viruses have a smaller genome, so there are fewer
genes to have to worry about. And you have this possibility that
you can isolate the genes of the virus because you can grow the
virus in large quantities. It's a simpler system, smaller
genomes. So a lot was learned using that paradigm.

The lesson I think that I and a lot of people drew was using
viruses as a probe or as a model often provided a lot of
information about the nature of genetic control and the processes
involved in going from gene to protein. So, hearing that there
was such a thing as tumor viruses and that they induced cancer in
animals was intriguing. But if you look at it, you would say why
couldn't you use these viruses in the same way, to study gene
regulation in mammalian cells, rather than just in bacteria? I
used to joke when I said that what I wanted to know was whether
the Jacob-Monod model for regulating gene function was as true in
mammalian cells as it was in bacteria.

Hughes: You didn't find the complexity of the mammalian cell daunting?

Berg: Well, I didn't, because I was not going to be studying the

mammalian cell genome's expression and regulation. I was going to
be looking at the expression of the viral genes after the virus
infects.

Hughes: I see.

Simian Virus 40

Berg: The viruses that we chose to work on had only five genes. They
have a very small DNA genome; a circular DNA molecule of only
about five thousand base pairs.

Hughes: Both SVAO and polyoma?

Berg: Yes. SV40 grows in human cells and primate cells; polyoma grows
in mouse cells.

Hughes: And their simplicity is at least partially the reason they are
research tools?

Berg: I think the simplicity really only became apparent in the mid-
sixties. SVAO was discovered in 1961, inadvertently. It turned
out that SVAO was a contaminant in the Jonas Salk polio vaccine.
The Salk vaccine was prepared from polio viruses that had been
grown on Rhesus monkey kidney cells. Virus was recovered in the
cell lysates without much purification and then inactivated with
an agent that kills the virus but doesn't destroy its ability to
act as a vaccine. It turned out that these rhesus monkey kidney
cells were infected with SVAO, which nobody had ever known. SVAO
stands for simian virus. It was discovered by taking polio virus
and injecting it into hamsters; much to people's dismay, the
hamsters developed tumors. That was very worrisome because the
same vaccine was being injected into kids. Therein lies one of
the things that we'll come to in the recombinant DNA controversy,
because we were using SVAO, and the question was, does SVAO
produce tumors in humans? It certainly produces tumors in
rodents. The question was, is working with SVAO dangerous?

Kornberg's Dedication to E. coli as a Research Tool

Berg: After hearing Dale Kaiser's lecture, I decided that what I wanted
to do was to stop working on bacterial systems and learn how to
culture mammalian cells and to use SVAO or polyoma as a model for
studying gene expression and regulation of mammalian cells.

Hughes: Were your colleagues behind this?

Berg: Arthur was furious. I won't say we ever came to blows, but there
were times when I was so furious with him because he was so
critical. He more or less said, "You're wasting your talent.
You're destroying your career. You have so much of a gift for
doing enzyme research. The only true path to knowledge is E.
coli," and so on and so forth. He was very narrow-minded. I
won't say he forbad me from taking that step, but he certainly
predicted complete failure. The fact that we didn't fail and that
we turned up a lot of very important new things about SVAO, which
I'll come to, made him even less happy. In fact, the term he used
is that I was a Pied Piper leading people astray, taking them away
from important basic research into this messy field of working
with uncharacterized systems, complex systems like mammalian cells
and so on.

Arthur and I have this debate to this day. For example, if
you want to study immunity, you can only study immunity in a
system in which immunity exists. You can't study immunity in E.
coli. But he won't concede that. He will argue that principles
and models that you learned from E. coli may be the key to unlock
the understanding of immunity. For sure, but at some point you
have to work with cells that display immunity. If you want to
study oncogenesis and tumor formation, you want to learn what the
genes are that are responsible for forming tumors. You're not
going to find out about tumor genes in E. coli. So, that's an
ongoing debate. We have it all the time.

And we'll probably have it tonight, because we're having
dinner with Senator Connie Mack, who is trying to increase funding
for the NIH. I'm sure that tonight at dinner Mike Bishop,
Kornberg, and I will get into a debate about which is the true
path to knowledge. [laughter] Kornberg will lament the fact that
people like me and Bishop have opened up vistas that have been
extremely informative and profitable in terms of research and left
E. coli behind. He talks about fashions in research, and the
fashion now is not to work on E. coli. The work which went on
over the last thirty, forty years, will not be used to its fullest
because people are now going off into other research areas.

In fact, if I would tell you some stories that are really
amusing: there was a time when I heard Arthur lecture Gobind
Khorana for leaving the work that he was doing on the chemistry of
nucleotides and nucleic acids to work on membranes, which Arthur
thought was a waste of his talent. This was after Gobind had the
Nobel Prize. I won't say he berated—that ' s probably too strong
of a word—but he certainly was furious with Francis Crick for
seducing his son Roger [Kornberg] to work on chromatin when Roger
went to Cambridge to the MRC [Medical Research Council].
"Chromatin was dirty. It was a mess. It was too complex." Yet
Roger made some of the major discoveries that opened up the whole
field of chromatin to a more sophisticated kind of study.

When I was chairman of the department [1969-1974], I had a
big fight with him about a professor in our department who also
decided to work on tumor viruses and went off and spent a year in
London at the ICRF. George Stark came back and began to leave
what he was doing, which was protein chemistry, to work on tumor
viruses. Kornberg read him the riot act at one of our retreats.
He just told him he was wasting his career, wasting his talent. I
was furious, and I told Arthur he had no right to be telling
people what to work on.

Anyway, this is a long story, and an ongoing debate that
we've had over many years, and continues. We differ over the

intensity of his feeling that working on E. coli is the only
worthwhile system and everything else is too messy. But in fact,
the science of mammalian cells has really blossomed.

Hughes: I understand that Arthur's approach was a relatively common one,
probably up until the late fifties, wouldn't you think?

Berg: Yes.

Hughes: The answers were to be obtained by looking at simple systems, and
the mammalian cell was too complex an entity and science didn't
yet have the tools to approach it.

Choosing a New Research Direction

Berg: What Arthur didn't understand, and what I tried to convey to him
on many occasions, was that ambitious, bright, young people want
to move away from where everybody else is working. They try to
open new fields. If they ask a question that takes them in a
totally new direction, that's exciting. They want that challenge.

Arthur was that way. He was a nutritionist. He was working
on feeding mice or rats, and he said he got fed up with just
studying what went in and what came put and not knowing what went
on inside. So, he left nutrition. Now, at that time I'm sure
somebody must have said, "You're going to damage your career,
because you are one of the leading people in this field. You're
going off to work on purified enzymes and take a year off to go
work with Ochoa and Cori?" Well, when he came back, he was the
hot, young guy in a new field.

I saw my position pretty much in the same way. The
bacterial field, particularly in the area of gene expression, in
outlines were already becoming quite clear. The Jacob-Monod-Lwof f
story was already the dominant paradigm. And yet there was
nothing known about gene expression in mammalian cells, in
eukaryotes--nothing! It wasn't a totally unnatural question to
ask: Are the mechanisms that work in bacteria also the ones that
will explain gene regulation in eukaryotic cells? Very few people
were working on that.

I was ambitious, reasonably bright, and had already made a
mark in traditional biochemistry. I was really interested in
trying to do something new, something different, that other people
were not doing. And I have no doubt, had Arthur been in my
position, he would have done exactly the same thing. I'm

absolutely certain. I think that attitude has driven a number of
other people in our department and made the department so
successful. Dale Kaiser went into working on a totally new system
in developmental biology. Dave Hogness who had been working on
bacteriophage X went off and started working on Drosophila
genetics. Each of them have become the leaders in the new fields
that they literally created. Some people can stay with what they
did as graduate students, postdocs, and follow along, and some are
very successful. But for me, I would get bored.

Sabbatical at the Salk Institute, 1967-1968

Berg: When I chose to work on tumor viruses, it was just a budding

field, and one of the leading people in it was Renato Dulbecco.
Renato came up to visit Stanford, and I asked him about the
chances of working at the Salk Institute. This was because of
listening to Dale Kaiser.

So, the question was, do tumor viruses express some genes
that cause the cell to behave like a tumor cell? I decided that I
was going to take the year off, learn how to grow mammalian cells,
and come back to Stanford and work on tumor viruses. That plan
did not meet with Arthur's approval; everybody else thought that
was great.

My assistant Marianne Dieckmann went with me to La Jolla. I
was due to get a postdoctoral fellow who was coming from the
Pasteur Institute to work with me. When I changed my plans to go
to the Salk Institute, he came there with me. So, we went down
there as a small team--myself , Marianne, and Francois Cuzin, who
had come from Francois Jacob's lab at the Pasteur Institute. We
started working with tumor viruses, adapting the strategies from
molecular biology. All the concepts that we had of regulation, of
the way bacteriophage multiply, how they lysogenize, we brought
with us to the animal virus field. When we came back to Stanford,
I was committed; that was the new direction we were going to go
in. And the work that was ongoing with the amino acid activating
enzymes sort of tailed off.

Establishing Research on SV40 at Stanford

Berg: I was away during '67- '68, and when I came back I built a new
laboratory, which had all the safety features — filtered air,

negative pressure, laminar flow hoods, and everything of that
sort. The point is I was committed; I was going to work in that
field. We did some important work of opening up a whole field:
finding mutations, characterizing the genome of SV40--it's a small
circular DNA molecule, 5243 gene pairs—and trying to determine
which regions of the DNA specified which gene. We worked out a
whole lot of new technology for doing that. It was built on
methods that we brought with us from the earlier work with
bacteriophages, which is usually the way science progresses.

Building on the Bacteriophage Lambda-£. coli Research

Hughes: Your concept was that what happens in E. coli infection is a basis
for thinking about what happens in mammalian cells?

Berg: Absolutely. For example, the virus chromosome is a small DNA
molecule; it has to be transcribed; the cell's transcription
machinery resembles that of bacteria in having an RNA polymerase
which it uses the triphosphates , and so on. So what you know
about transcription in E. coli, you're going to immediately apply
to transcription in eukaryotes. It was possible to map the RNAs
and to characterize them, that is, when they're made after the
infection. As it turns out, when the virus enters the cell, part
of its genome is transcribed into what we call early messenger
RNAs. Those early messengers make early proteins.

Those early proteins then start the system of replication,
and you then begin to express a new set of genes, so-called late
genes. The late genes encode the shell of the virus, very similar
to that of the bacteriophage. Bacteriophage lambda T-4 do almost
the same thing: they enter E. coli and express part of their
genome, early genes; they make early proteins; early proteins
start replication. The replication initiates late transcription
which results in the proteins that form the phage. Very similar,
right? But now you've opened up a whole new world of how a
mammalian cell does that. And you can begin to study the
mechanism by which mammalian cells carry out the basic steps of
gene expression.

Drawbacks of Using Commercial Reagents

Hughes: What difference does it make that students today come to mammalian
cell research without the experience that you and others of your

generation had? Do they lose something because of not having
experience with phage and E. colil

Berg: I think the big difference today is students are unaware of the
amount of work it takes to prepare all of their own reagents.
When Kornberg was studying DNA replication, he had to synthesize
all the radioactive deoxytriphosphates. To the people in his lab,
it was like being sentenced to Siberia when it was their turn to
take several months out and prepare the labeled triphosphates.
Today, students just write an order and buy it. They buy all
their enzymes; they don't purify any enzymes—ever . And when they
buy them, they have no respect for their use. They never worry
about how much activity there is; they just dump in some amount.
The manufacturer says use five microliters; they don't know what
five microliters contain. They don't know if the enzymes have
impurities and so on and so forth.

Those of us who grew up in a more traditional mode worry
about all these things. If you get a result that's funny, maybe
it's funny because your enzyme preparation is contaminated, not
because there's some funny phenomenon. But people who have moved
into the animal field, who work with Drosophila, are very
sophisticated.

Biochemical and Genetic Approaches

Berg: Paramount today is the genetic approach. In working on the Beadle
biography,1 I've come to recognize the power of the approach which
he exploited, which in fact even preceded him. If you have a
complex biological phenomenon or system, you can approach it in
two ways. Kornberg 's approach is to break open the cell and try
to identify some reaction you're interested in, and purify the
components responsible for the reaction. The other approach is to
make mutants—ones which block the phenomenon, obliterate the
phenomenon, change the phenomenon, or prevent the reactions that
you're interested in studying from happening.

The various steps that are involved in this process are
dissected by making mutations in each and every one of the steps.
Consider a complex pathway in which a very simple precursor is

1 At the time of the interviews, Dr. Berg and Dr. Maxine Singer were
collaborating on a biography of George Beadle.

converted via ten steps to an end product, and each step is
catalyzed by an enzyme. You could try to purify all of those ten
enzymes and work out the detailed chemistry of each step. Or you
could start by making mutations which identify the steps, because
when you make a mutation that blocks a step in the process the
substrate of that step accumulates. Because they accumulate, the
intermediates in the reaction can be identified.

Having mutants provides a powerful tool to look for the
protein or the genes which encode the protein. If you have cells
that can't carry out one of the steps in the pathway, you can now
use such cells to isolate the gene, because introducing that gene
into these cells overcomes the block. These are the two different
paradigms for trying to analyze complex biological systems.

Mutations are the predominant approach when we have no idea
what reactions are involved in the complex system under study. Fly
behavior is a good example, for example, phototropism. Normal
flies move to a light source, and it is possible to obtain mutants
that fail to do that. You get mutants that can't see, mutants
that can't fly, and mutants that can't translate the light signal.

This [genetic] paradigm is what people are doing today.
It's no less honorable than purifying enzymes. Some enzymologists
put their faith in enzymology, but I suppose I'm more liberal. I
admire, accept and encourage people who want to try new ways to do
things and don't insisting that purifying enzymes is the only way.

Fluid Disciplinary Boundaries and Multidisciplinarity

Hughes: Is it difficult to label what people in the biochemistry

department actually are? Are they biochemists, geneticists, or
cell biologists?

Berg: I think that's happening in all areas. In the Pharmacology

Department, you couldn't distinguish two- thirds of the people over
there from the people in my department. Similarly, in
Microbiology, people are doing the same kinds of things that are
being done in Biochemistry. The artificial definitions don't
prevail anymore. Many scientific problems have now gotten to be
very complex and really need multiple and different kinds of
approaches for their solutions.

One of my jobs here at the Beckman Center is to create
mechanisms that bring people together from different departments,
ones who bring different perspectives, different skills, different

technologies to a problem. The ability to solve complicated
problems rarely exists in any one department any longer. The
problems are too complicated. So, what we're trying to do is to
create interdepartmental programs around themes, around areas of
interest.

Kornberg tends to resist these new approaches. Arthur
remains a strong advocate for the enzymological approach, using
pure enzymes. He can admire new approaches, but he'll still say,
"You don't really understand it until you get the enzymes out and
purify them." That's good. It serves a very important function.
You can make the argument that the purpose of the mutational
approach is to identify the genes responsible for the individual
steps. Ultimately, however, to understand that pathway, you must
purify, identify, and characterize the proteins that perform those
steps. Nobody denies that.

One time when we were recruiting a new faculty member,
Arthur and I interviewed a young woman who had already done some
really fantastic work at the MRC [Medical Research Council] in
Cambridge, using the nematode as a model for studying development.
We brought her over. She gave a brilliant seminar. Kornberg
asked her why she wanted to be in a biochemistry department if she
was a developmental biologist. She explained that the approach
she was using, which was to obtain mutants, was only to get into
the system and that ultimately she wanted to be able to understand
these mutations at the biochemical level. Then Arthur asked her,
"Why should the biochemistry department be interested in you, a
developmental biologist?" And she said, "I didn't ask to come;
you invited me to come here." [laughter] She was pretty good.
She's at UCSF now and one of their real stars.

Hughes: Who is that?

Berg: Her name is Cynthia Kenyon. She's now one of the leaders in the
nematode field and using nematodes to study aging. She's been
making mutants whose life spans are much longer than normal.
Interestingly enough, Arthur's son Tom, at UCSF, is using
Drosophilia mutants to study their embryonic development. So
there you are.

Research Leading to Recombinant DNA Work
Hughes: Let's discuss your recombinant DNA work.

Berg: A reasonable starting point is to ask how did we ever get to
thinking about recombinant DNA while working on SVAO?

In moving from one field to another, you bring to it some
background, some insight and some prejudices, if you will. As I
was preparing to go off on sabbatical, I was getting more and more
involved with using genetic tools to study how amino acyl-tRNAs
work in protein synthesis.

Collaborating with Charles Yanofsky on Suppressive Mutations

Berg: One of my colleagues in the biology department, Charles Yanofsky,
and I became very close friends, and we began to collaborate on
certain experiments. He had demonstrated that certain kinds of
mutations could reverse the effects of other mutations; some
rautational suppressors appeared to work through mutations in
tRNAs. That is, if a tRNA is supposed to read a codon A-B-C, you
can get a mutation in the gene that specifies this tRNA so it now
reads A-B-D, and not A-B-C. As a consequence, a particular amino
acid will be inserted into the protein chain in the wrong place.
Such mistakes can reverse the effects of a mutation in the protein
coding gene; hence the term suppressor.

Using Phage as Transducing Agents

Berg: We were studying mutations which affect tRNAs that change the

reading or the translation of the genetic code. In order to do
that, I was beginning to learn to do a lot of genetic crosses with
bacteria and using bacteriophage for what we call transducing
agents. Lambda is one of a whole series of phages which, after
integrating into the chromosome and then coming out, incorporate
pieces of chromosome into their own chromosomes.

Hughes: By mistake?

Berg: More or less by mistake. So, they integrate at a particular
place, and with some low frequency, they come out, but
incorrectly, picking up a piece of bacterial DNA while losing a
bit of their own. When such virus particles infect another cell,
what do they do? They bring with them the information that they
stole from the first cell. So, you can transfer genes from one
cell to another by bacteriophages . And that proved to be a very

powerful technique in altering the genetics of cells by bringing
in genes from different sources.

Hughes: Could you specify the gene to be carried?

Berg: Yes, because some bacteriophages , like lambda and another one

called phiSO, integrate in only one place in the bacterial genome.
So when they come out, they can only bring out the pieces that are
alongside. There are other phages, however, that cause the
bacterial genome to be fragmented into small pieces, and when the
phage is assembled, it picks up cellular DNA pieces at random.
The pieces it picks up are roughly the size of its normal genome,
and the particle looks like a bacteriophage, but it has a piece of
bacterial DNA instead of phage DNA. The pieces are picked up at
random. Consequently, some phages are carrying one gene, another
phage is carrying a different gene, another phage is carrying a
different gene, and so on.

This notion that viruses could carry genes from one cell to
another really was a reality, and I was using it all the time.
It's called transduction. So phage could transduce cells with a
variety of genes from any cells in which the phage was grown.

Developing a Transducing System for Mammalian Cells

Berg: Well, while 1 was working on the tumor viruses, the question I
asked myself was, are mammalian viruses capable of picking up
mammalian viruses and bringing them into new mammalian cells? In
other words, could you, in fact, develop a transduction system
that works for mammalian cells, just as the bacteriophage work
with bacterial cells? The reason for believing that was possible
is that when I was at the Salk Institute, phage particles that
carried cellular DNA were discovered. The question was, could
those viruses that are carrying cellular DNAs be used to transform
other cells? After making some calculations, it became quite
clear that SV40 and polyoma couldn't do it, because their genomes
were very small. Their genomes comprise only five thousand base
pairs, and you can't pack more into the virus particle. So, the
most you could possibly pick up from a mammalian cell would be
five thousand base pairs.

When bacteriophage picks up cellular genes, it loses a
little bit of its own. But lambda is fifty thousand base pairs;
SVAO is only five thousand. So, the question is, how much could
you lose, and how much could you actually pack in? The answer was
that the amount you could pack in to the virus particle is hardly

big enough for a single gene. And even if it was big enough for a
single gene, the likelihood that any particle contains the gene
you're interested in or knew how to look for was problematic, like
looking for the needle in a very large haystack.

I knew that we had to find a way to move genes from one cell
to another. We thought that if we couldn't find virus particles
that had picked up a specific cellular DNA, then why not make
them? We wondered if we could we take a set of pure genes and
insert them into the SV40 genome in vitro. If we could, then we
might use the virus DNA's ability to enter a mammalian cell,
integrate into the chromosome, and carry with it whatever had been
attached to it.

Hughes: The reason that you were interested in the DNA of SVAO was simply
as a transporting mechanism?

Berg: Absolutely. That was the notion we had. If we could create such
a system, it would really greatly enlarge the capability of
studying mammalian cells and doing molecular and cell biology. A
question was, what could we attach to SV40?

At that time in Dale Kaiser's lab, Ken-ichi Matsubara was
working with a small piece of bacterial DNA that could replicate
in E. coli. It was part lambda bacteriophage DNA associated with
three genes from E. coli. This plasmid could be purified and
obtained in pure form. The plasmid, called lambda dv gal, was
about five thousand base pairs in length and contained three
bacterial genes and the little piece of lambda DNA which allowed
it to replicate in £. coli. We had pure SV40 DNA, and we knew
that SVAO DNA could be used to infect mammalian cells, whereupon
new viruses are produced, or the DNA integrates into the cells'
chromosomes.

We had pure SV40 DNA which contains about five thousand base
pairs in the form of a ring. We thought that if we could make a
molecule which contains SV40 DNA as well as the bacterial genes,
we could ask if, after introduction into a mammalian cell, the
bacterial genes are expressed. That was the question we set out
to answer.

Lambda Bacteriophage with Complementary Tails

Berg: First we had to figure out how do you join two DNA molecules. A
colleague at Stanford, Dale Kaiser, had been studying a lambda
bacteriophage ' s cohesive or sticky ends. The phage DNA has

single-strand protrusions from each end which allow molecules to
join end-to-end. Under certain conditions, lambda DNA could join
end to end to make long chains or under other conditions they
circularize. So the existence and behavior of cohesive ends in a
lambda phage DNA pointed the way to do the joining. If you make
complementary tails on DNAs, those DNA will join to one another
through the formation of hydrogen bands.

Hughes: You mean literally make the tails, synthesize them?

Berg: Phage lambda DNA has them naturally. What Dale Kaiser and Al

Hershey and a few other people all discovered simultaneously was
that these ends are like Velcro. They're cohesive, because
they're complementary to each other. And so under the appropriate
conditions, a linear molecule of lambda will form circles, or
[join] end to end to produce long chains.

Synthesizing "Sticky Ends"

Berg: So we set about to learn how to synthesize synthetic sticky ends,
because the two DNA molecules we had did not have cohesive ends.
Once you were aware of the fact that cohesive ends exist naturally
and allow DNA molecules to join one to another, you would say the
trick is to make synthetic ends. Because strands of A's and one
with T's pair, it seemed logical to put tails of A on one [DNA
molecule] and tails of T on the other, and after mixing them, they
very likely would join. So, the task became one of creating
sticky ends with an enzyme.

DNA Ligase

Berg: Now most of the enzymes for doing this whole operation were in

Kornberg's refrigerator, and we had access to all of them, which
was one of the great things about the department.

Hughes: There were several people involved with isolating ligase, not all
of them at Stanford.

Berg: Three labs get credit for discovering the enzyme DNA ligase
virtually simultaneously. Bob Lehman, Kornberg, and Martin
Gellert.

Hughes: If you've got base pairing, where does the ligase come in?

Berg: Normally, SV40 DNA is a closed circle, that is, there are no nicks
or gaps; each chain is absolutely continuous. If you circularize
a linear molecule as I described it, a DNA ligase is needed to
join all the ends. In the case of lambda DNA, when you
circularize it, there's perfect fit right up to where you make the
ligase join the ends creating the closed circles. With uneven
tails of A's and T's, circularization occurs, but these are gaps.
These have to be filled in before ligase can join the ends.

Recombinant DNA

Making Recombinant s of SV40 and Lambda dv gal

Berg: Making synthetic tails was the first step [sketching] [See diagram
A, page 68a]. Let's see, these are A's, and these lengths are
variable because we had no way of controlling their lengths. With
dATP and an enzyme (deoxynucleotidyl transferase) A's are
polymerized onto the ends. We try to put on somewhere in the
range of a hundred to a hundred and fifty A's per end. But the
two tails are certainly not the same length. Now T's are added
with dTTP and the same enzyme. When the two DNAs are joined,
there are four gaps because the dA and dT tails are not all the
same length.

Hughes: I see that.

Berg: To fill in the gaps and seal the ends we used DNA polymerase I,
the Kornberg enzyme, which fills in the gaps, and DNA ligase to
seal the ends. All we had to do was create the cohesive ends,
anneal them, add DNA polymerase and ligase, and covalently closed
circles would be formed, one half of which would be SV40, and the
other half lambda dv gal.

Hughes: That's very clear.
Berg: So, it's very simple.

Peter Lobban's Research on Recombinant DNA

Berg: Actually, Peter Lobban, who was a graduate student in Dale

Kaiser's lab, had come up with the same idea on his own. One

68a

AAAAA

AAAAA + TTTTT-

-TTTT

Paul Berg: "Arrows denote gaps to be filled in before DNA ligase can close
the circle."

could have used G's and C's for cohesive ends, but he also used
A's and T's on each end. What's necessary is that they be
complementary, that is, form base pairs and join the two DNAs to
one another. So this was what we developed in 1970-71, "69.

The Jackson, Symons , Berg Paper, 1972

Berg: A postdoctoral fellow in my lab, who had done his graduate Ph.D.
work here in biology with Yanofsky, came over and joined my lab
and actually did this experiment. And it took not more than about
seven or eight months.

Hughes: Who was that?

Berg: David Jackson. And there was a sabbatical visitor from Australia
named Bob Symons. So, the paper is actually Jackson, Symons, and
Berg.1

Hughes: If you were to single out one paper, would that be the paper upon
which the Nobel Prize was based?

Berg: Yes, I think so. If you read the paper, you see that in the

discussion it lays out that the ability to join two DNA molecules
together allows one to begin to make all kinds of recombinants.
We used lambda dv gal, but any piece of DNA would work. We
anticipated that some technology would evolve in the future to
isolate individual genes, and therefore individual genes could be
plugged in.

Lambda dv gal plasmid itself has the capacity to replicate
in E. coli. So if this molecule is introduced into E. coli, it
could be replicated and maintained as a plasmid. If put into
mammalian cells, we presumed that it would integrate. As it
turned out--Stan Cohen was right—we opened up the lambda dv gal
at a position that destroyed its ability to replicate. And
therefore this molecule would not have replicated in E. coli.

Hughes: How did you interpret that at the time?

1 D. A. Jackson, R. H. Symons, and P. Berg, "Biochemical methods for
inserting new genetic information into DNA of Simian Virus 40: Circular
SV40 DNA molecules containing lambda phage genes and the galactose operon
of Escherichia coli," Proceedings of the National Academy of Sciences
[PNAS] 1972, 69:2904.

70
Berg: We didn't because we didn't try to do it.

Complexity of the Berg Recombinant DNA Method

Berg: Now, this technique of making recombinant DNAs was viewed as being
complicated and probably beyond the ability of most labs. It was
assumed that it could be done only in my lab, probably because we
had all the enzymes locally and the expertise in how to use them.
And that was certainly correct.

Once we decided that we were not going to try to propagate
these recombinants, our critics breathed a sigh of relief and
said, "Okay, we've been spared. If Berg is not going to put these
recombinants into bacteria, there's no longer a problem."

Hughes: Other people wouldn't be able to do it.

Berg: Couldn't do this, right. David Hogness, one of my colleagues, was
the only person who actually used this (method] to construct
recombinants with Drosophila DNA.

The Cohen-Boyer Recombinant DNA Cloning Method

Berg: But the whole picture changed when it was discovered that when
certain restriction enzymes cleave DNA they create natural
cohesive ends.

Hughes: So now practically anybody could do it.

Berg: Now anybody could do it. You could buy an enzyme, take two DNAs,
cut them, mix them, tie them together and, presto, a recombinant
DNA.

Hughes: I gathered from your MIT interview that Asilomar I was originally
conceived as a two-step conference.1 But the idea of having the
second conference was temporarily dropped. It was only when the

1 Interview with Paul Berg, by Rae Goodell, May 17, 1975, Recombinant
DNA Controversy Oral History Collection, Institute Archives, MIT,
Cambridge, p. 28-29. Berg was interviewed again for MIT, by Charles Weiner,
on April 17, 1978.

Cohen/Boyer experiments were disclosed that the need to consider
their safety implications arose.

Berg: The implications of the Cohen/Boyer cloning and the ease with

which recombinants could be made was taken up by a small group of
seven people that met at MIT in April of 1974. That meeting
resulted in the so-called Berg letter,1 or the moratorium letter.

Recombinant DMA Controversy

Concern about Berg's Proposed Experiment with SV40

Berg: We didn't ever try to put the lambda dv gal-SV40 hybrid into E.
coli because when it was discovered that we were making this
molecule, there was concern about putting SVAO into a bacterium
that inhabits people's intestines. The concern was that SVAO
carries tumor genes, and cancer might be spread through this kind
of infection.

So, reports of our work in 1971- '72 created a big furor.
Nick Wade wrote a book called the Ultimate Experiment.2 The
ultimate experiment was to put the SV40-containing hybrid plasmid
into E. coli. We decided not to do that because we couldn't be
sure that this would not produce a bacterium which could get out
of the lab and infect people and possibly populate their
intestinal tract with bacteria that carried cancer genes. So, we
never did the experiment. We never tested whether it could grow
in bacteria.

Hughes: One of the debates was, could bacterial genes not only replicate
but also express protein in mammalian cells?

1 "Potential biohazards of recombinant DNA molecules," Science 1974,
185:303 (July 26, 1974). The signers of the letter were: Paul Berg, David
Baltimore, Herbert Boyer, Stanley Cohen, Ronald Davis, David Hogness,
Daniel Nathans, Richard Roblin, James Watson, Sherman Weissman, and Norton
Zinder.

2 Nicholas Wade, The Ultimate Experiment: Man-made Evolution, New
York: Walker and Co., 1977.

Berg: That's right. That was why we did the experiment. We planned to
put this plasmid into mammalian cells. That was not a problem; we
could have done that, but that was put off because Dave Jackson
left the lab for a job at the University of Michigan.
Furthermore, concerns arose and expanded about the safety of
working with these DNA molecules themselves. Being infectious,
could such molecules escape into the air and get into bacteria?
These really were very absurd kinds of concerns.

Berg's Involvement

Berg: But the fact is that I got distracted and got involved in this

whole debate about whether these molecules were safe or not. As a
consequence, a lot of people who were leaving bacterial work to
work on tumor viruses raised the question of whether SV40,
polyoma, and adenovirus were a hazard for man.

In response to these concerns, I got involved in organizing
a conference--Asilomar I [ 1973] '--that most people don't know
about. It was held at least two years before the Asilomar
Conference on Recombinant DNA [February 1975] to consider possible
hazards of working with tumor viruses.

Biosafety at Stanford and the Salk Institute

Berg: Remember, I mentioned that when I came back from Salk, I built a
new laboratory, equipped with the latest biosafety equipment,
because there was concern on the part of people in my department
who were working outside my group about whether they were being
unduly exposed to potentially tumor-causing viruses.

Hughes: Did those safety measures pertain at Salk?

Berg: Salk was very loose. They had just these little Plexiglass hoods,
and you did all your work in there. Everybody was working on
SV40, and they didn't worry about it at all. Generally,

1 The publication arising from this conference is: Biohazards in
Biological Research, Proceedings of a Conference held at the Asilomar
Conference Center, Pacific Grove California, January 22-24, 1973, A.
Hellman, M.N. Oxman, and R. Pollack, eds., Cold Spring Harbor Laboratory,
1973.

scientists didn't worry about whether working with SV40 was
dangerous to them. But then you bring it into an open lab, with a
lot of people who are not involved in the work. I don't remember
exactly how the word got around and why the technicians and
dishwashers at Stanford would have been worried about somebody
working with SV40. Perhaps it was at a departmental meeting. I
had just become chairman [1969-1974] of the department, and so I
was very sensitive to this kind of unrest and uncertainty. To
mitigate these concerns, we built a lab with filtered air,
negative pressure, laminar flow hoods, in an adjacent building.
Everybody was reasonably confident it was safe.

Asilomar I Conference, 1973

Berg: Out of this conference, for which there was a big report and

book,1 there was a recommendation to draw blood every six months
from everybody working in a lab and to determine if they had
antibodies as a measure of their exposure to the virus they were
working with. If you had antibodies, it meant you were exposed to
the virus and had been infected. As it turned out, in my lab
almost everyone became seroconverted.

Hughes: That procedure arose from the first Asilomar conference?

Berg: Yes. [Indicates photomicrograph on book cover] That's SV40 on
the cover, from my slides. [The arrangement of the virus
particles] happened to form a question mark.

Hughes: Yes, isn't that striking.

Berg: That's the proceedings of the conference, the papers that were
presented and the final recommendations. I made the closing
remarks. Essentially what it says is, we don't know whether these
viruses are oncogenic for man, and asks what steps should be taken
to protect ourselves. We had in mind the problem, How do we
proceed in the face of uncertain safety? Do we ignore it, or do
we try to do something?

Not too many people know about the Asilomar I conference
proceedings. For example, here are designs of the kinds of hoods

1 Biohazards in Biological Research, Proceedings of a Conference held
at the Asilomar Conference Center, Pacific Grove, California, January 22-
24, 1973, A. Hellraan, M .N. Oxman, & R. Pollock, eds., New York: Cold
Spring Harbor Laboratory, 1973.

that laboratories should construct. We brought in people who were
in charge of biosafety at the NIH, and they described how rooms
should be arranged and so on and so forth—facilities and
equipment available for virus containment.

Hughes: Was there overlap of the people who attended Asilomar I and II?

Berg: Oh, yes. There were many of the same people who are in here

[referring to Asilomar I book]. Here's a chapter on laboratory
hazards from aerosols. Those people were at Asilomar II, or they
were on the RAG [Recombinant DNA Advisory Committee], or the
guidelines called on them to provide information about safety.
Now that I look at this list of attendees, a good many of the
people were also at the Asilomar II conference.

One of the steps we proposed was to initiate a prospective
study, to periodically collect blood samples from people who were
working in the field and store them. We still have them, frozen
away. The purpose was to keep track of anybody who developed
cancers and to check with their prior exposure. Working with
laminar flow hoods, in negative pressure labs were also amongst
the recommendations that came out of this conference.

These procedures set the stage for entering into an era
where we were going to work with infectious organisms whose
complete properties couldn't be predicted. Clearly, as we began
to manipulate viruses and make mutants, there was a possibility
that we might make something that would be more dangerous to the
workers as well as to the people around us.

The Moratorium Letter and the Meeting at MIT

Berg: Some of the people who were at the MIT meeting had also been
participants in the Asilomar I meeting.

Hughes: Do you remember who they were?

Berg: Richard Roblin was one; Jim Watson, Dave Baltimore, Norton Zinder,
were also at Asilomar I.

Berg: The reason Roblin was invited to the meeting was because he had

written an article in Science about gene therapy which focused on
manipulating mammalian cells by virus infections. So, he was
invited to come to that meeting.

Hughes: Why was he provoked to write that article?

Berg: Well, the whole notion of genetic engineering of animals was not
new. Josh Lederberg had speculated on it earlier. There were a
number of science fiction scenarios; in fact, oftentimes gene
therapy was cited as justification for doing genetics.

Hughes: Arthur Kornberg testified in the Senate in 1968 on genetic
engineering. '

Andy Lewis and Natural Adenovirus-SVAO Recombinants

Berg: A man named Andy Lewis, working with adenovirus at the NIH, had

raised concerns about adenovirus-SV40 recombinants . Adenoviruses
are big viruses of about thirty thousand base pairs. What Lewis
found is that cells that were coinfected with SV40 and adenovirus
produced recombinants which had replaced part of the adenovirus
with SVAO sequences.

These were called adeno-SV40 hybrids, and they propagated as
viruses. But they were defective; generally, when adenovirus
genes are replaced by SV40 genes, the recombinant virus can't
multiply. But Lewis discovered a class of adeno-SVAO hybrids
which were nondefective and could replicate. He was very
concerned, because we're all infected with adenovirus and if SV40
got out, it might form adeno-SVAO hybrids which could propagate
and spread SV40 genes. Consequently, a very big part of the
Asilomar I meeting addressed the concern about what to do about
these adeno-SVAO hybrids.

Hughes: What would be the purpose in an evolutionary sense for SV40 and
adenovirus to be able to join?

Berg: There's no disadvantage or advantage. It happens accidently.
Hughes: That doesn't happen very often, does it?

Berg: No. But here they'd cloned these out; they had pure populations
of these adeno-SVAO hybrids. People found them very useful and
wanted to use them as tools.

Hughes: So you were creating an artificial circumstance.

Berg: That's right. Andy Lewis to this day is concerned about such
events. There was just a conference at the NIH, "Is SV40

See the oral history with Arthur Kornberg, cited p. 8.

Tumorigenic for Man?" Because a number of people have come down
with tumors with SVAO genes in them. They're saying it just took
a long time for this to happen. One of the sessions at this
recent meeting was called "Hazards Associated with Modern Research
Methodologies . "

James Watson's Stances

Berg: Coming out of the Asilomar I conference, Jim Watson decided to

forbid the use of feline leukemia viruses or cats at Cold Spring
Harbor because he was so worried about whether these viruses could
cause cancer in man.

Hughes: Yet one of the amazing things that happened at Asilomar II was
that Watson changed his tune about the dangers of research with
tumor viruses.

Berg: That's right. If you're cynical, you might speculate on why. Jim
was at the MIT meeting that came out with the Berg letter. He was
absolutely supportive, insisting that we had a responsibility to
warn the general public and scientists about the potential dangers
of cloning.

One of the consequences of the Asilomar II conference was to
mandate that research could proceed only under conditions which
guaranteed the organisms you were working with would not escape
from the lab. I had already invested in building a P3 [physical
containment 3] laboratory that minimized that risk, and it was
expensive. Jim was now pushing working with tumor viruses, SVAO,
at Cold Spring Harbor, and he realized that if such safe
facilities were required he would have to invest and build much
secure facilities there. Jim could certainly calculate what the
cost would be to build the kind of facilities being proposed at
Asilomar, and he knew that not doing so would impede their ability
to compete. I suspect he also came to the conclusion that we had
been rash at the first meeting in presuming risks that he now
thought were unreasonable.

Hughes: At one point you accosted him over his change in stance. Can you
remember what he replied?

Berg: Jim never would have admitted that there was an economic component
to his argument, or his ability to compete. I think what he said,
and he may have felt that honestly, is we made am mistake in the
Berg letter by concluding that there was great concern.

Hypothetical Risks

Berg: I think if you reflect, as we all did later, on the basis for this
concern, it was all hypothetical. There was not strong reason to
believe that what we were doing would be dangerous. It sounded
dangerous. We wondered what might be the consequences if you put
genes that confer resistance to antibiotics into bacteria that
infect man; you'd prevent the use of antibiotics that cure
whatever that bacteria caused. That sounds pretty worrisome, and
we suggested that such experiments should not be done. Second,
putting genes that specify toxins into bacteria that could inhabit
man should also not be done. But then when you come down to the
rest of it, it was pure hypothesis. We could imagine you might
inadvertantly pick up oncogenes from mammalian DNA, incorporate
them into plasmids, and put them into bacteria. Well, so what?
As it later turned out, even if you do, it doesn't make any
difference. It turns out it's safer to work with oncogenes that
way then it is to try to work with the viruses which carry them.

Hoof and mouth disease is one of the serious virus
infections, so all work on hoof and mouth disease is done on Plum
Island, an island off the coast of Long Island. But you can
fragment hoof and mouth disease [virus] and clone its genes, and
it's quite safe in that form. Hepatitis can only be grown as DNA
segments, as plasmids. We began to realize that in some ways you
could say it was safer to be using recombinant DNA.

Nonmicrobiologists and Research on Infectious Organisms

Hughes: Asilomar II was February, 1975. You began working with SV40 in

1971?

Berg: Nineteen sixty-nine.

Hughes: Do you remember when Lewis began working with adeno-SV40 hybrids?

Berg: Yes, it was around '71.

Hughes: So, by Asilomar II, there was five or six years of research
experience with--

Berg: Not with recombinant DNA, since the Cohen/Boyer experiments were
done during '73, '74.

Hughes: I'm calling what you had done recombinant DNA, and in a sense,

Lewis's research, even though I know that the adeno-SVAO hybrids
were not a deliberate creation. What I'm trying to assess is how
much experience you collectively had had with recombinant
organisms by Asilomar II. And it seems to be roughly six years of
research.

Berg: Right. But only a very small number of people had had that
experience. Remember, the [Cohen-Boyer] recombinant DNA
breakthrough made it possible for anybody to do anything . This
was recognized, and was one of the driving forces for the
moratorium letter. There was a lot of people who had no
experience working with potentially pathogenic organisms and they
would be moving into the field. In fact, it was common for
biochemists and molecular biologists who had been working with E.
coli to grow up E. coli in five-gallon jugs and dispose of some
down the drain. E. coli was viewed as innocuous, and some people
might have volunteered to drink it. But microbiologists and
bacteriologists knew that E. coli was not innocuous.

Everybody was pipetting viruses by mouth; that's the way we
worked. The reason people who worked with viruses were
seroconverted was because when you suck up a column of a solution
with a virus in it, you have a vapor, an aerosol at the top, and
that gets taken up [in the digestive track].

We realized that in fact the technology now had changed the
way people were going to do things, and most of those who were
going to be working in the field were totally inexperienced and
unaware of the most trivial safety measures. And so part of the
rationale for the letter was to bring this to people's attention.

Hughes: I know from talking to microbiologists that they had scathing
remarks to make about the laboratory safety techniques of non-
microbiologists . '

Berg: Microbiologists used a loop. I don't think a biochemist knew what
a loop was made for.

Hughes: This confluence of disciplines, that we talked about, has so many
ramifications. One of them is bringing in disciplines that don't
have a long background in working safely with pathogens.

1 For example, see Edwin Lennette, Pioneer of Diagnostic Virology with
the California Department of Public Health, Regional Oral History Office,
The Bancroft Library, University of California at Berkeley, 1988.

Berg: That's right. If biochemists broke and spilled an important

experiment, they'd suck it up without thinking, even if it was
something dangerous. Their goal is to save the experiment.

Achievements of the Research Moratorium

Berg: Well, if you were working with really hazardous things, you'd say
that kind of behavior is unacceptable. But if you were working on
problems at open benches, you don't know how such people think
about risks. What does it take to do so? What kind of ethics or
whatever does it take for somebody to say, wait a minute, you
don't want to do something so stupid that it's dangerous to
yourself, to your family, to your co-workers. It doesn't take any
higher calling for somebody to say, "Hey, wait a minute, we ought
to think a little bit about what we're doing to see whether it's
safe."

Hughes: And that's what Asilomar II and that complex period of history
did?

Berg: That's right. Today, there's no question that it impeded some

research. But my argument is that impedance actually benefitted
the research in the long run. For one, I think we didn't generate
the kind of public opposition that could have easily stopped the
research. Because we took the initiative, and brought attention
to the problem, and tried to deal with it, people accepted that we
were conscientious, well-meaning, and responsible.

Second of all, I don't know how much work on cloning human
genes could have been done right from the beginning. We didn't
know how to walk, no less run. We barely could crawl. When the
Asilomar constraints said you can do this under these conditions
and those conditions, people learned how to do the cloning under
safe conditions. People learned to adapt so that now nobody ever
used mouth pipettes; people worked in hoods; people had to take
care. And before you knew it, it was possible. The technology
had improved. People's approach to things had changed. You could
now go after human genes. So, I don't think that we lost a lot by
saying you couldn't clone human DNA for the first year or two.
But it certainly prevented people, or called attention to the fact
that you had to think about what you were going to do before, not
after. And you had to think about, was it sensible? Was there
any kind of a risk? Could I learn what I want to learn another
way?

Hughes: Well, there were some examples of things that had gone wrong,

particularly in Britain. I understand that they colored the Ashby
group's considerations. What was it? Smallpox?

Berg: Yes.

Hughes: There had been some recent deaths in a British laboratory. As you
say, if the research momentum had continued unabated—

Berg: Somebody would have done a dumb experiment.

But you also have to remember that there were scientists,
who had a very different perspective—Science for the People kind
of thing. They were primarily left-leaning people. The Vietnam
War spawned a whole lot of people to be very suspicious, not
accepting. There were claims being made about certain genes
predisposing to criminality. And this group in Boston [Science
for the People] reacted to that.

Had we not called attention to what we were doing
[recombinant DNA research], they would have. I believe they would
have said to the public, "Look at what these guys are doing; this
is really dangerous stuff. It's the first step to genetic
manipulations of man," and blah, blah, blah, which is what they
tried to do. But given that we had raised the safety issue first
and tried to deal with it, I think their message was blunted. And
while they were harassing us much. of the time and were successful
in some places, Cambridge and so on, in the end they didn't win.
And the science moved forward.

So as I look back on the period, even though we were wrong- -
wrong is probably not the right word; certainly our assessment of
the potential risk was incorrect—by calling attention to it, I
think the whole thing was better off in the long term. The
science that has come out of it has just been absolutely mind-
boggling. And so that's what in the end will justify it.

Transduction

[Interview 3: September 30, 1997]

Lysogeny and Transduction

Hughes: Dr. Berg, my goal today is not to talk exhaustively about the
biohazard issue, which has been well-covered in the historical

literature.1 Instead, I want to focus on the science. What were
the technologies that made the recombinant DNA work possible?

Berg: Well, there were really two lines of investigation that were
important. I think I ended my last interview talking about
lysogeny. Lysogeny is a phenomenon in which viruses that infect
bacteria can integrate their chromosome into the chromosome of the
infected cell. And then they are maintained as if they were a
normal part of that organism's chromosome. They're replicated
each cycle. The cells are perfectly healthy. They reveal some
new properties as a result of having acquired the virus
information. But with low frequency, this mutually acceptable
state breaks down and the viral chromosome pops out of the
cellular chromosome and replicates, killing the cells and
producing the virus. That state is referred to as lysogenic,
meaning that the cells, while they're perfectly normal and grow
perfectly well, enter a state after the virus is activated, and
the virus kills the cells by lysing them.

Now, if you ask, what is the virus that comes out? Is it
exactly the same as the virus that went in? And, 99.999 percent
of the viruses that come out are exactly the same as those that
infected the cells originally. That is, they are excised from the
cellular chromosome perfectly accurately. But, occasionally, they
actually come out with some of the adjacent cellular genes. And
so, the virus that comes out now is different than what went in.
It has lost something of its own chromosome and picked up some of
the cellular chromosome. Such viruses, when they infect the next
cell, will be able to transfer genes from the original cell they
were in to the new cell they infect. That process, called
transduction, was discovered many years ago by Norton Zinder and
Joshua Lederberg. So depending upon where the virus integrates,
it's able to pick up genetic information of the cell closely
linked to it.

Other Forms of Transduction

Berg: There's a second phenomenon of transduction in which another

virus, a different one, goes in and infects the cells and kills
the cells. And, in the act of killing the cells, it literally
pulverizes the cellular chromosome into bits and pieces. In the

1 See, for example: Susan Wright, Molecular Politics: Developing
American and British Regulatory Policy for Genetic Engineering, 1972-1982,
Chicago: University of Chicago Press, 1994.

packaging event, which leads to the production of new virus
particles, these bits and pieces of cellular chromosome are
inadvertently packaged into the viral particle. As a consequence,
a population of viruses is produced which carries different pieces
of the cellular chromosome as well as their own. If you looked at
these virus particles, you couldn't tell the difference as to
whether they had their own chromosome or whether they carry pieces
of the cellular chromosome. They infect cells; they bring in this
new genetic information. And this genetic information can then
replace what is present in the cell. And so, you now get a new
genetic property. This process is referred to as transduction.

So, there are two kinds of transducing viruses. One of them
is what we call lysogenic, the virus goes in, integrates, stays
there for however long, spontaneously pops out, most of the time
accurately. Occasionally, it picks up cellular genes alongside
it. And if you know where the virus goes, you can actually then
transfer genes that are adjacent to the site of integration.

Hughes: This was all well known?
Berg: All well known.
Hughes: By when would you say?

Berg: I was doing this in conjunction with Charles Yanofsky, who's a
geneticist. This is the technique of modifying bacterial cells
and introducing new kinds of genes in them. For that purpose we
used bacteriophage lambda or phi 80. Those are two kinds of
phages. They each integrate in different places in the host
chromosome. We used the phi 80 phage because it often could carry
the genes that controlled tryptophan synthesis, and we were
studying tryptophan mutants. We could transduce genes from one
cell into another and create cell lines that had useful genetic
properties for our experiments.

The lambda phage goes into a different part of the E. coli
chromosome, and it carries different sets of genes when it comes
out. The P, phage is different because it picks up random pieces
of the cellular DNA. That's also very useful because in any
population, a virus that comes out of an infection will carry
genes that you're interested in studying. Using Pj you can
transfer any genes.

So, the important conceptual point is, there was a way to
transfer genes from one cell to another, and it had proven to be
extremely useful and powerful in setting up experimental systems
for genetic studies.

Hughes: Is this a potential evolutionary mechanism?

Berg: Usually these viruses are quite specific for the cells they

infect. So, it isn't that they spread their genes throughout a
population. But certainly within a certain group of organisms,
genes are flowing back and forth. No question about that. I
suppose if you put a selection on, that is conditions which favor
the growth of cells that contain one set of genes, those will have
preferential growth, and the others will die out.

Hughes: So, there was a natural mechanism that you took advantage of.
Berg: That's right.

Hughes: What couldn't you do with it experimentally that you hoped to do?
Why devise an artificial laboratory mechanism for transferring
genes?

Berg: Because you could, in fact, use conditions that selected for just
the kinds of organisms you want. By doing the transduction in
several ways, we were able to adapt that natural phenomenon to our
advantage. Now, this was true of bacteria and bacteriophages. 1
would attribute a very large part of the burst of genetic
knowledge during the 1960s to the astute use of these
bacteriophages. That certainly helped. Another thing is, once
these viruses come out, you can isolate the ones that carry these
cellular genes, and then you begin to analyze the sequence.

In one case, it was possible to sequence a large part of one
region of the bacterial chromosome because it was now highly
enriched in the bacteriophage DNA. After all, the viral
chromosome was tiny compared to the cellular chromosome, so you
get an enormous enrichment. If you harvest the virus, you've now
looked at a small portion of the cellular chromosome and can
analyze that. And that was done.

Transduction of Mammalian Cells

Hughes: You said that you had a natural system that you were taking

advantage of. What I see coming next, with recombinant DNA work,
is that you created constructs for scientific purposes. No longer
were you just taking advantage of what nature had already
provided.

Berg: That's right. But the important thing is to realize that in

mammalian cells, there was no such natural system. No viruses

were known that could transduce genes to mammalian cells. Well,
let me put it this way. When I went to the Salk Institute for a
sabbatical, it was to learn about how to work with mammalian
cells. The motivation formed from the fact that viruses had been
so influential and important for the development of the molecular
biology of microorganisms that maybe studying the interaction of
animal viruses with animal cells would give us the same kind of
insights.

The polyoma virus I studied has a very small chromosome,
only five genes. So, if you wanted to study how a cell expresses
its genes, instead of looking at how it expresses its own genes,
why not look at how it expresses the virus genes once they enter
the cell—a much easier system. So, when I went to Salk, it was
to begin to understand something about how these tumor viruses
multiply in a mammalian cell.

We chose the tumor virus because it too mimics, to some
extent, lysogenic viruses. It can integrate into the cellular
chromosome. And we thought, well, perhaps under certain
conditions it could come out and carry with it genes that are
adjacent to where it had integrated. During that year, we had a
lot of success studying some interesting features about polyoma
infection of mouse cells.

One of the things that others discovered was that there were
virus particles coming out carrying cellular DNA. That looked
like the P! phage . So the question was, could we in fact use such
viruses in the same way that the bacterial people had used P, as a
way of transporting genes into mammalian cells? The idea was to
grow the viruses in one kind of cell, then take the population of
viruses that come out and infect another population of cells, and
ask whether interesting genes were transferred from one to the
other.

Hughes: How at that time did you distinguish viral from mammalian DNA?

Berg: We could label the DNA of the virus, and we could follow its

transactions, if you will, once it entered the cell. Two, once we
have the DNA of the virus, we can use that DNA as a probe. When
the virus enters the cell, it's transcribed and makes messenger
RNAs. If we had the pure DNA, we could use the DNA to detect
those messengers. But since isolated genes from mammalian cells
were not available, there was no way to follow the transcription
or expression of mammalian genes.

Remember that the mammalian genome is larger and more
complex than the bacterial genome, and the amount of DNA is a
thousand times greater than is present in a bacterium. So, the

idea of being able to follow the expression of mammalian genes was
very complicated. There were a lot of puzzles. For example, when
people tried to look at something that was supposed to be the
equivalent of messenger RNA, they found an enormously complex
mixture of RNAs of varying sizes; most of it never ended up as
messenger RNA. That was a real puzzle. In bacteria, you could
measure transcription. An RNA molecule is colinear with the
segment of DNA from which it is transcribed. But in mammalian
cells there was this mess, a real mess, 98 percent of which never
makes it into the cytoplasm.

Hughes: You didn't find that intimidating?

Berg: No. Some people did. Kornberg tried to persuade me not to get

involved in such a messy system; "You're wasting your talent," he
told me. He was really very, very critical of the decision to
enter this field. However, I was convinced that we were beginning
to know a lot about the bacterial genetic system--how it's
expressed, how it's replicated, and so on. There were elaborate
theories of regulation, of the messenger RNA concept. One had to
stop and ask oneself, Is all of this unique to the bacterium? Is
this the way things happen in higher organisms? Well, I wanted to
learn if this whole system of messenger RNAs, transcription,
operators, repressers, polymerases, and so on, existed in
mammalian cells. How do you begin to study mammalian cells? That
is intimidating. The virus was the key. The virus was the way to
get into that system and simplify it.

Hughes: So, the virus approach made it acceptable to you to do this very
complicated, risky research?

Berg: Right. In fact, it turned out to be correct; the virus was the
simple way to be able to look at it. And people just went to
different viruses. We began to work with SV40; other people
worked with polyoma, adenovirus . But the virus was the entree
into studying how mammalian cells deal with a piece of DNA. Use a
small piece of DNA [the virus] so that you can distinguish it from
the cellular DNA.

During the year at the Salk it was discovered that viruses
coming out of the infected cells seemed to be carrying some
mammalian DNA sequences. We thought, perhaps is this the analog
of the P] transduction system? If you make the calculation, you
soon realize that SV40 can only package about 5,000 base pairs of
DNA, whereas the bacteriophages that we were using before could
package 50,000 b.p.

Hughes: What are the limitations?

Berg: The limitations are the size of the viral capsid or shell capsid.
The capsid has to be built, and only so much DNA can be stuffed in
it. So, 5,000 base pairs of DNA go in. Now, if you ask, given
the size of the mammalian genome, 3 billion base pairs, a 5,000
base pair segment of it is a very, very small fraction of the
total. So, the question is, any one virus particle could only
contain an inf initesimally small amount of the cellular
chromosome. If you were looking for a particular gene, it would
be very rare. And if it was very rare, you would have to have an
incredibly powerful way of detecting its transfer and ultimate
function. And so we quickly realized it was hopeless to use this
as an analog of P,. Of course, we knew nothing about the
likelihood of being able to incorporate a whole gene. We didn't
know the size of mammalian genes. Now we know it would have been
impossible.

At that time we thought mammalian genes were about the same
size as bacterial genes. You might have been able to package them
but it would have been so rare that only maybe one in a billion
particles would actually contain the gene of interest in
functional form. And then you would have the job of finding a
needle in the haystack. You'd have to have an enormous population
of mammalian cells infected by an enormous population of virus
particles in order to detect the transfer of one gene.

Hughes: So, detection is really key, isn't it?

Berg: Logistics, detection, and the packaging limitation in the virus
were all things that precluded what we had in mind, namely that
you could transfer genes using SVAO viruses as vectors. If you
had viruses that could carry much more DNA, you might have had a
chance.

More on the Biohazards Controversy

Berg: The Morrow experiment, if I remember correctly, would have been
early '74.

Hughes: And the first Cohen-Boyer paper was published in November 1973.

Berg: [June] "73 was the Gordon conference, because Boyer reported the
first cloning experiment which got a lot of people uptight. And
' 74 was the Morrow experiment . The ' 73 experiment reported at the
Gordon conference got people excited and triggered the National
Academy of Sciences to get involved. It got me involved.

120

MIT Meeting to Discuss Biohazards, 1974

Berg: As we were readying the meeting at MIT to discuss how to advise
the Academy, up comes the Morrow et al. paper. The Morrow paper
shows that anything can be inserted into a plasmid and be cloned.
That raised the stakes. Stan Cohen said, "I'm getting telephone
calls from all over the world, people asking me to send them
pSClOl. What should I do?" So when I went to MIT for the
meeting, it was with the background that it was now clear anything
could be put into E. coli.

Some of the things that Stan Cohen said people were calling
him about sounded ominous! Should the tetanus toxin gene be put
into E. coli and enable E. coli to do something it can't
ordinarily do? So, those were the things that led to our
consideration of a moratorium. Interestingly enough, Stan was not
involved in that committee meeting at MIT, nor was Boyer, nor was
Hogness, nor was Davis. But, as soon as we brought back the
outline of what we had decided on at that meeting, they
immediately wanted to have their names associated with it. That's
how they became signatories of the "Berg" letter.

Hughes: Am I remembering correctly that you were the organizer of that MIT
meeting?

Berg: Yes.

Hughes: Had you invited them?

Berg: No. I had invited primarily people who had been involved in

Asilomar I, who had some experience in thinking about the risks of
this kind of experimentation. Jim Watson, because he had been
outraged by some of the things that people wanted to do with
viruses. Dave Baltimore, because he clearly had been one of the
principals in working with animal viruses, particularly tumor
viruses. So, all the people who came to that meeting were people
who had been involved in that first Asilomar meeting.

Berg: I also invited Maxine Singer but she couldn't come. I don't

remember if we invited anybody else that couldn't come. But we
felt that seven was a reasonable size. Remember, we were not on a
mission to do what we did. [laughter] I had been asked by the
president of the National Academy of Sciences to advise the
academy on how to respond to the concerns that had been voiced at
the Gordon conference. It was a very limited request. I just
took it on myself to say that I wasn't going to advise the

121

president of the academy on my own. And what I would do is try to
bring some people together that I thought would be thoughtful and
do something about it and just asked these seven or eight people.
It turned out there were six others beside myself.

The "Berg" Letter, July 26, 19741

Berg: But when I came back to Stanford, I reported that the group's

decision was to publish a letter in Science and Nature, calling
attention to the potential biohazards and offering recommendations
on how to proceed. Stan, and Herb, and Ron Davis, and Dave
Hogness immediately wanted to have their names associated with
this.

Hughes: Why?

Berg: I don't know. Stan Cohen and Dave Hogness later thought the whole
thing was stupid. Nevertheless, they signed the letter, as did
Jim Watson. At the [Asilomar II] meeting, Jim Watson was most
vociferous about calling for a moratorium. Why they did it? I
don't know. Maybe they thought, as we did, that there was enough
uncertainty that it was a reasonable thing to do. Maybe they did
it because they wanted to have their name associated with
something that would have that flavor. I just don't know. But,
we did not exclude them. There was never a question of voting,
should we or should we not. These people wanted to put their name
to it.

My recollection is that I probably thought it was a good
thing, because they were active participates, their names were
very well-connected with recombinant DNA already. Therefore, if
their names were on it, this [letter] would have more of an impact
on the rest of the community.

Hughes: Did they come to you and ask to be put on the letter?

Berg: Yes. Well, I'm sure I circulated a draft of what we had come up
with. And they said, could they put their names on it too?

Hughes: I can see that it would work to support the letter's

recommendations to have people sign this letter who were actually
involved in these experiments.

1 Paul Berg and ten signatories, "Potential biohazards of recombinant
DNA molecules," Science 1974, 185:303 (July 26, 1974).

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Berg: I think that was in the equation. There was never any thought

that they should be excluded. And so, I don't think there was a
big argument, for example, pros and cons. It seems not an
unnatural thing and might very well have been obvious that if
you've got the very people who were most involved in the work,
actual participants of the work, the letter would have more force,

Don't forget, the letter was addressed to colleagues around
the world; it wasn't addressed to the local community. The point
is, if you had names like Cohen, and Boyer, and Hogness, and
Davis, in addition to the other people that had been on it, the
letter would have more impact, more acceptance.

The Nobel Prize in Chemistry, 1980
Singling Out Berg

Hughes: Let's go on to a discussion of the Nobel Prize, even though it's a
few years forward in time. I read the article in the November
1980 of Science which quotes the press release from the Swedish
Royal Academy: "Berg was the first investigator to construct a
recombinant DNA molecule, i.e., a molecule containing parts of DNA
from different species."1 Do you think that phraseology is meant
to give the reader a fully descriptive idea of what the research
was about? Or was it a way of tacitly explaining, to those who
really understood the body of research, why you had been singled
out rather than someone else, namely that you were the only one to
have joined DNA from different sources?

Berg: I don't know who is the author of that statement; the actual

statement for the Nobel Prize talks about my early work as well as
the recombinant DNA. Not as explicitly as that. Essentially, we
worked in nucleic acids and recombinant DNA. I don't even know
where the statement you quoted comes from.

If you talk about recombinant DNA, you talk about joining
two different kinds of DNA molecules together, and our experiment
was clearly the first to do that. What Peter Lobban did was make
dimers. What Sgaramella did was make dimers. And whoever this
other guy was?

1 G.B. Kolata, "The 1980 Nobel Prize in Chemistry," Science 1980,
210:887-889.

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Hughes: Jensen.

Berg: Jensen made dimers. Is that a distinction? I don't know. I
disdain the kind of identif ication--"the father of genetic
engineering", all that kind of hype that comes around. I have
never claimed that we developed cloning; we didn't. What we did
was develop a way to join two different DNA molecules together
outside of a living cell—period.

Berg's Opinion of His Best Work

Hughes: If you were the Nobel committee and could choose amongst your own
scientific achievements, would you choose the recombinant
DNA work?

Berg: You mean, would I have chosen that bit of work for me to get the
prize?

Hughes: What I'm really asking is, do you consider it to be your best
work?

Berg: No, no, no, not at all. But, you see, that's not the criterion

that the Nobel committee uses. The man who shared the prize with
Kornberg, [Severe] Ochoa, got the prize for--presumably--having
discovered the means for making RNA. But in fact we know that the
enzyme he discovered doesn't make RNA at all. It's like that
terminal transf erase; it's a dumb polymerase that just polymerizes
nucleotides at random. But Ochoa was one of the towering figures
in biochemistry. Everybody would have said that this guy was
going to get the Nobel Prize. What did he get it for? He got it
for something which he would not have identified as his most
notable achievement. I think you can say that for any number of
Nobel awards.

I might have told you very early in our interview process
that I thought the most significant and most innovative piece of
work that I did was as a postdoc when I joined Kornberg 's lab, in
the discovery of this new class of compounds for activating
molecules for assembly into larger molecules. I think that was
much more creative.

124

Speculations on Why Berg Was Chosen

Berg: But remember, recombinant DNA had two things going for it. One
was it was at the focus of a public policy debate all over the
world, in Sweden as well. And two, it had an enormous impact.
What the Nobel Prize often rewards is the way science is changed
as a consequence of that discovery.

Carl Cori was one of the great figures of biochemistry in
the 1940s. He and his wife Gerty shared the Nobel Prize for
discovering an enzyme that breaks down glycogen. If you ask any
student today who Carl Cori was, they wouldn't know. And two, if
you asked them if they thought that glycogen phosphorylase had a
major impact or changed the face of biochemistry, they would
answer no. But, in its day, it was an innovative finding.
Remember, they had already established themselves as premiere
biochemists .

So, I'd like to think that the Nobel Committee also
considered the highly regarded work that I had done long before
the recombinant DNA. Perhaps some people were supportive because
I was a leader in the public policy part of it. And in some
circles that seems to be more important than the scientific part.

Hughes: Really?

Berg: Yes. I don't know whether the people on the Nobel committee used
that. More likely, however, is the enormous impact and the way
[recombinant DNA technology] changed the way biology is done.
Anybody, looking back, could ask how this enormous new kind of
science began. Where does it go back to? It starts with the
demonstration that you can join DNA molecules together. And then
a lot follows from that.

I was invited shortly after the public policy issue broke-
publication of the moratorium letter—to come and give a lecture
in Sweden, which the king attended. It was a big public lecture.
Swedish opinion was much more interested in the issues of
responsibility in science, and ethics, and safety. And so, I
could have become a hero, I don't know. There might have been
some people that would have regarded what I did as being
courageous. I don't know. I didn't think it was courageous.

But, people look at that whole episode in different ways.
It has really been amazing. We focused on it very narrowly: is
[recombinant DNA research] safe, is it not safe? People saw it as
raising a big ethical debate and us displaying an enormous level
of ethical concerns. But we saw it as a public health issue.

125

Hughes: Well, you have been criticized for narrowing the debate to the
issue of biohazards.

Berg: That's right. And, I think that diminishes any attribution of
high ethical standard. If you said we were in this to really
raise the consciousness of the world about the impending change
and the way things were going to be done, we didn't do that!

Hughes: I think associated in the public mind is the idea of scientists
policing themselves.

Berg: Yes.

Hughes: That idea could have influenced the Nobel committee.

Berg: After the award was announced, there was an editorial in Wature,
or a little blurb about the award. My recollection is that the
guy who wrote it certainly acknowledged that idea could easily
have had an impact on the choice of Berg. I mean, nobody tried to
say, you didn't deserve it because the science you did was trivial
or whatever. Without being too modest, people recognized the
science that I had done was first class. The recombinant DNA
thing is a thing with a big impact. It's easy to latch on to that
and say that's what you give the prize to. I don't know if I
would have gotten the prize for the previous work alone.

So, if you add it up, there's a first-class science
background, there's some kind of association with a very important
scientific breakthrough, and then a leadership role in trying to
manage the impact of that breakthrough. When it's taken together,
people say, well, okay. There's another point as well. The Nobel
prize is limited to three individuals.

Hughes: And, they have to be living.

Berg: They have to be living. There have been a number of instances

where people were passed over for the prize because it would have
exceeded three. In other words, there were four people that
contributed equally, or this one person was unequivocally
associated, and there are three others, and these three don't get
it. In fact, such a thing actually happened. Phil Sharp and one
other person, Richard Roberts, got the prize for discovering
introns. Now, the person at Cold Spring Harbor who actually
discovered the anomaly that led to the insight [Tom Broker] didn't
get it. And when people talked about why he didn't get it, it was
explained that it was because he and his wife had collaborated on
it and that would have made four people.

Hughes: That's tough.

126

Berg: Okay, so now the question is, why didn't Cohen and Boyer get it
instead of me?

Hughes: Or, why didn't Berg, Cohen, and Boyer get it?

Berg: Because, the Nobel Committee believed, I think, that the critical
and important contributions to recombinant DNA were cloning and
sequencing. Cloning without sequencing is trivial. Sequencing
without having specific cloned pieces of DNA to sequence is also
useless. Developing both were technical feats, and the two
together are what really made the molecular genetics revolution.
People cloned DNA and sequenced it. Okay? So, why not Cohen and
Boyer, and Gilbert and Sanger? That's four. So, you could say,
one compromise is not Cohen and Boyer, but Berg. It's difficult
to know what the thinking of the Nobel Committee was.

Hughes: In speculating how the biohazards controversy may have elevated

you in the Swedish consciousness, I wonder if Cohen's and Boyer 's
commercial ventures worked to their disfavor in the eyes of the
Nobel committee?

Berg: I don't know. The secrecy that shrouds the decisions about the
Nobel are remarkably well kept. The Swedes have managed to keep
that process unpolluted by leaks. There may be speculations, and
there are people who try to hype themselves or somebody else by
saying they're being considered, etc. But, what I know from my
Swedish friends who are involved in the process, it is very
tightly guarded.

If somebody were to suggest to them that there were
extraneous issues that were considered or played a role, they
would deny it vehemently. People involved tell me they spend the
entire summer researching a few candidates, going back through
every paper, every collateral paper; trying to document priority
is very, very important to them. In the end, this whole process
winnows down to a few names, and then it's the respective Nobel
academies that vote on them.

Recommendations from the individual committees have been
reversed; that is, committees have come in with a recommendation,
and the whole academy has rejected it and selected another
candidate from the small group. So, who knows? Yes, in the final
vote of the academy, it's quite conceivable that, without anybody
conceding it, sentiment plays a role, because they all have to
vote. And, if some guy says I admire this person for what he
stood up for and what he did, it could sway their vote. But, I
don't think those issues would have any impact at all with the
screening and review committees.

127
Influences on the Choice of the Nobel Award

Hughes: I thought of Gary Mullis when we were discussing the fact that the
prize is usually given for a body of research.

Berg: In that case, he had done nothing before.
Hughes: So there are exceptions to the rule.

Berg: Michael Smith, who was the other guy who got the prize that year,
made one contribution when he was a postdoc of Rhorana's. He
hadn't ever distinguished himself in other ways; I've known him
for a long time. The idea of being able to make targeted
mutations in DNA the way he did it certainly has had an enormous
impact. And, my guess is, that's why he got it. If you ask, was
it a great intellectual breakthrough, a great intellectual
inspiration, the answer is no.

Hughes: Why did the most preeminent prize in science go to two
technological achievements?

Berg: I don't know which ones you're referring to.
Hughes: I'm referring to PCR and mutagenesis.

Berg: People have speculated, and I have no insight at all, as to

whether there are contending forces on the Nobel Prize decision.
Some would like to make it more practical; some favor more
theoretical. Some favor more basic, others more applied. It
almost seems to alternate. Like one year it's a group of
physicists who developed a machine, another one it's a cosmologist
who has come up with a grand theory.

And the same thing has happened in biology. When I say
basic, it could be the crystallization and determination of the
structure of a protein. And then the next year, it's somebody who
has developed a whole series of compounds that are promising for
cancer chemotherapy. Those two are very different kinds of
intellectual activities. I don't know whether within the academy
they debate this kind of issue.

Nobel's objective was to reward advances in science that had
an impact on society, and he suggested that it be for a discovery
in the year of the award. Well, very few of the prizes have been
given for things that have had impact in that year, because,
rightfully so, some period of time is needed to see whether the
discovery is just a flash or whether it has some lasting effect.
And so you have to wait.

128

Yet More on Recombinant DNA
[Interview A: November 5, 1997) ft

Terminal Transferase

Berg: The existence of terminal transf erase was long known. It was a
curiosity, because it was the first enzyme that actually
synthesized DNA without a template. That's not quite true.
Kornberg had shown that DNA polymerase would synthesize some kind
of funny polymer without a parent template. But, in this one
terminal transferase, you needed a primer. You needed DNA, and
all it did was add nucleotides on to the ends.

My recollection is that in Bollum's work it wasn't known if
transferase would add on to the appropriate 3-prime end of a
double-stranded DNA if it was blunt. It had to be a protruding
primer end; that's what Peter Lobban essentially discovered and
quickly related to us.

Creating Permuted Linear Molecules with "Tails"

Berg: In fact, I thought a little bit about it after our conversation.
Our original plan was to open the SVAO circle at random sites,
because we knew we were going to put tails on the ends. So, it
didn't make any difference where we opened it. And by cleaving
the DNA at random sites, we would have a population of linear
molecules that were permuted, that is, they would have different
ends because they were opened at different places. That would
minimize the risk that where we were actually making the
attachment to the other molecule would interfere with some
essential function in the SV40.

So, we spent a lot of time using an enzyme called pancreatic
DNase, DNase-1. It had been discovered by others, and we
concurred that if you do it in the presence of manganese, you make
primarily a single cut, and then it stops. So, we were cutting
with pancreatic DNase, making linear molecules with different
ends, polymerizing A's and T's on to the end, and then joining
them together. But when John Morrow discovered that EcoRl made a
unique cut, we didn't know exactly which gene the cleavage was in.
It turned out it was in the gene that specifies the capsid
protein.

129

If I remember correctly, we used the Rl-cut linears, because
they were always uniform. And because they were uniform, we knew
that they had 5-prime protruding ends, and that's not the kind of
thing that you want this terminal transf erase to be adding to. We
needed a way to remove the 5-prime extensions to leave 3-prime
extensions, and that was done with an enzyme which had been
discovered at Stanford, called exonuclease-7 . That enzyme
specifically degrades double-stranded DNA starting at the 5-prime
end and going in, therefore leaving 3-prime extensions. So that
was essentially the strategy and how we evolved to it.

Choosing the Best "Tails'

Berg: The only other thing that I forgot to mention was, we spent a lot
of time trying to figure out which were the best tails to use. We
originally started out to ask whether G-C tails were the best to
use. It didn't make any difference in principle which you used if
you wanted so-called cohesive ends. But it turns out it was very,
very difficult to polymerize G's onto the ends of DNA. There was
a standing joke in the department that if you're going to have any
trouble with anything in DNA, it's going to be with G. People
tried to make dGTP and that always failed and the others worked
well, and so on and so forth.

The reason why we were having trouble is G forms internal
polymers with itself. And so if you polymerize onto the end and
make a long tail of G, the chances are it is going to form some
kind of funny structures. In fact, G-C forms triple-stranded
structures. When that was discovered, we realized using G-C was
causing bad things. So we went back to using A-T. I don't think
we ever published the ins and outs and failures because we
published in PNAS , and PNAS has a limited amount of space. We
went right to the direct thing [A-T]. Actually, Bob Symons, who
was an Australian visitor, did a lot of the work trying to produce
these G-C tails.

The Jensen et al. Paper and Biochemical and Biophysical Research
Commun ications

Hughes: Have you said all you care to say about the Jensen paper?
Berg: Other than I didn't know it existed. I never heard of it.

130

Hughes: What about the journal itself?

Berg: BBRC [Biochemical and Biophysical Research Communications]!

Hughes: Yes.

Berg: I was an editor of it for a while in its earliest days. I know I
wasn't an editor at that point. Although, my memory--. It
started out as a journal presumably to allow short hot new
findings to be published. It certainly did that for some things.
But after a while, it accumulated a lot of junk. I mean just
things that people might have identified as critically hot papers
the way they're referred to today. I went off it [as editor]
because it was getting to be a nuisance. You see, the articles
are quite short because of limited space. They were reproduced
from your submitted text, thereby circumventing the need for
redactory and all of that business. It was intended as quick
publication; quick because they would just photocopy what you sent
them. It never had a very good reputation. It was viewed as "bio
quickies". I just decided I didn't want to be on it anymore. I
don't remember exactly when it started.

[Berg indicates Jensen paper] This is volume 43, 1971, so
you can see it must have started way back in the sixties. It came
out every month, and it was just a nuisance. I don't think I ever
read the bio quickies after I left the editorial board. I mean I
rarely look at it. But people do read it, do refer to it,
particularly people who are worried about somebody scooping them.
There's a journal that publishes just the table of contents of
various journals. So, people have resorted to essentially
skimming the titles. I don't remember ever seeing the Jensen
paper.

Hughes: Does the fact that Jensen et al. chose to publish in this journal
suggest that they knew that they had something hot? You
characterized the journal as a place for hot papers.

Berg: No. It had two features, one is you could submit short

communications, and they were published quickly. And, they were
almost unreviewed.

Hughes: The summary to their paper doesn't mention commercial

applications. I wonder if they knew the significance of what they
had done?

Berg: Actually, the last sentence is interesting. "Polynucleotide

ligase"--DNA ligase--"does not covalently join the single strands
of these synthetic catenanes." In other words, if you put A's and
T's on the ends, and then they join, there are going to be gaps

131

because there's no way to control how long the tails are. So you
can have twenty- five on this one and ten on this one, and they'll
form ten base pairs, but then there's a big gap. He obviously
didn't appreciate that since he couldn't control the length of the
homopolymer tails. That's why we and Peter ended up realizing
that when you hybridize the two and they join, DNA polymerase and
the four triphosphates can be used to fill in the gaps and ligase
to seal them.

Hughes: Jensen hadn't done that?

Berg: I haven't read the paper, but in the last sentence, it seems to
indicate that he's unaware that there are gaps, which would be
amazing. Oh, it says, "The catenanes formed by mixing T7 DNA
which contained synthetic homologous ends were apparently not as
well formed as those which occur in nature... We have been unable
to catalyze covalent joining of our T7 DNA catenanes using £. coli
polynucleotide ligase, even though numerous experimental
conditions were used including variations in temperature, salt
concentration and enzyme-substrate level." It never mentions the
fact that the ends are unlikely to have been perfectly matched.

"Catenanes of T7 DNA molecules with various lengths of
homopolymeric ends were also not joinable." Last paragraph:
"Ligase joining during concurrent repair DNA synthesis was also
attempted under conditions identical with those described by
Goulian and Kornberg." But, these were unsuccessful.

This was submitted March 12, 1971. I don't have my
notebooks to know where that stood in terms of our work.

Hughes: I don't remember when the Jackson, Symons, Berg paper was
submitted. '

Berg: [Berg scans publications for submittal dates] These are all
November '72.

July 31, 1972.

132

The Stanford Biochemistry Department's Industrial Affiliates
Program

The Chemistry's Industrial Affiliates Program [IAP]

Hughes: What I really want to talk about today is the commercialization of
the science. I thought that the place to start is with the
biochemistry department's Industrial Affiliates Program. Does
that seem appropriate to you?

Berg: Yes.

Hughes: In 1970, you wrote to Carl Djerassi saying that you were "taken",
that was your word, by the brochure he had sent to you on the
Industrial Affiliates Program in the Department of Chemistry, and
that you were interested in starting something similar in the
Department of Biochemistry.1 Well, it apparently took almost ten
years, because the first time any such idea is mentioned in the
faculty minutes is in 1979. 2 The program didn't get off the
ground until 1980. Was there a reason that it took so long to get
going?

Berg: I had just become chairman of the department in 1969. So in 1970,
if that's the date of that letter, I was charged with the
responsibility of helping develop resources for the department.
It struck me that the chemistry department had hit on a mechanism
which was really very interesting because it generated a lot of
money .

You realize that in 1970 our department did not have
something it could go out and sell as easily as it did in 1979.
We were a good biochemistry department. We were very highly
thought of. Maybe many people would have thought we were number
one. But the question is, what did we have to offer to industry?

By contrast, chemistry is cranking out graduates who go into
the chemical industry, and more likely the chemistry department is
doing research that's much more relevant to the chemical industry
and the pharmaceutical industry. Carl Djerassi is a terrific

1 Berg to Djerassi, May 25, 1970 (Berg papers, Green Library,
Stanford, S358, box 2, folder: 1970 A-H) .

2 Minutes, faculty meeting, Department of Biochemistry, October 17,
1979 (Arthur Kornberg papers, SC 359, Green Library, Stanford, box 5,
folder 1979).)

133

salesman, and given his connection with the pharmaceutical
industry, he was able to actually organize at one point forty
companies at $25,000 per. So [Chemistry was] pulling in a lot of
money. We didn't have anything like that, but we were well
funded. Part of the resistance in the biochemistry department
was, who needs an IAP!

Broaching the Idea of a Biochemistry IAP

Hughes: Do you remember that you broached it to the department after the
interaction with Djerassi?

Berg: Oh, yes, I'm sure I did.

Hughes: If I remember that letter correctly, one of your arguments is that
the federal funding of science is dropping off. Industry has
benefitted all along from academic science; it's time for it to
pick up some of the financial burden.

Berg: That's right. That's essentially what my interpretation was.
[Berg skims copies of archival documents which Hughes has
collected.] Okay, it gets picked up by Arthur Kornberg in 1979. '
So, the only thing you have is my letter to Djerassi that's as
early as 1970.

Hughes: That's right.

Berg: Also, there's a '67 letter in which Kornberg planned to visit at
du Pont, and they wrote to him about that.2 I remember Arthur
coming back and just being totally disillusioned by the attitude
of industry, and the way they did research and so on. Arthur
didn't know anything about the affiliate program in the chemistry
department.

1 Memo, Arthur Kornberg to Dale Kaiser, September 10, 1979 (Kornberg
papers, SC359, Green Library, Stanford, box 5, folder 1979).

2 Burt C. Pratt to Arthur Kornberg, October 11, 1967 (Kornberg papers,
SC 359, Green Library, Stanford, box 26, folder: 1967 A-L).

134
Stanford Relationships with Industry

Berg: I learned at that time that Stanford had forty Industrial
Affiliates Programs going in the university.

Hughes: In 1970?

Berg: I think so. Stanford was really a very entrepreneurial place.

The aeronautical and engineering departments all had these ongoing
relationships with companies, and that, I think, reflected
Stanford's close relationship with industry, which led to Silicon
Valley. The faculty were all involved, so departments nurtured
these kinds of relationships, and they were allowed to blossom
unfettered. If somebody was entrepreneurial enough to go out and
create a program, nobody kept tabs on them as far as I know.

My recollection doesn't allow me to tell you that I brought
it up to the department. The letter actually mentions something
about a decrease in federal funding. I remember we had a crisis
during my chairmanship when there was a threat that the training
grants were going to be dropped.

Hughes: Right, I remember seeing a reference to that.

Berg: And the training grants were vital to our program. There was this
threat that Congress was going to do away with training grants. I
went to Washington and lobbied, and so on and so forth. And,
probably it was in response to that that we were looking for new
sources of funding.

Hughes: Which you didn't come up with?
Berg: I don't know the dates well enough.

Program Project Grant, Institute for Research on Aging

Berg: But, one of the things that the department landed was a program
project grant from the Institute for Research on Aging. The
department banded together four, five, six people, and we then
made a proposal to the aging institute, and they funded us. It
only terminated about two years ago. We held the grant for about
four cycles of five years each. So we may have well have gotten
it during this period. We have notes in the department; you could
find out when we started the aging grant . The aging grant brought
in a fair amount of money.

135

But what happened is, the politics changed, and Congress did
not disband training grants, so we never lost the training grant.
So it's conceivable that the reason nothing ever happened out of
this first notion about the affiliates program was that the
department was well funded. If the training grant was secure, my
guess is we would not have developed sufficient enthusiasm for
doing the affiliates program.

Sentiment Against lAPs

Hughes: But it wasn't opposed because of any feeling in the department
that an affiliates program wasn't appropriate?

Berg: There were those feelings; there were some. I know that after we
started our program, and I went around the country, and when I'd
be visiting at Yale or at Cambridge, I mentioned the affiliates
program, and some people said, That's not a thing that academics
do.

I always justified it that we were doing was what we
normally do here: we teach. We weren't making proprietary
contracts with our affiliates. We weren't giving them first
access to any discoveries. All we were really doing was providing
expertise that was keeping them abreast of what was happening in
their field. And, I saw that as an educational mission. We were
just getting our tuition in different ways; we were getting it
through companies.

Functions of the Biochemistry IAP

Hughes: I remember seeing in one of these documents that the point of the
program was not to provide specific information for specific
industrial programs, but to provide general knowledge, as you're
saying, in this field in which you were expert.

Berg: That's right. It gave companies access to faculty. That is, the
original thing was they could send somebody to visit the
department each year to meet with faculty and students and
postdocs. We would arrange for them to have sessions with
students and postdocs for the purposes of their attempts to
recruit, and we would send them preprints of our papers before
they were published, and they would get these quarterly. And, at
the end of the year, they would get a bound volume of all the

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departmental papers. They had no proprietary rights to any
discoveries, materials, or inventions, or anything like that, and
that was it.

Once we mounted the program, everybody in the department was
really strongly committed to it. Everybody agreed that they would
go and visit. Furthermore, each company would have a visit from
somebody in the department who would spend the day talking to
scientists and give a seminar on their own research, and so on.

I dubbed this the Friends of Biochemistry, because that's
the kind of affiliation I was hoping to sell and also would expect
to have, namely, we're going to help you; you're going to help us.
The notion of obligation wasn't ever really broached as a selling
point because I think most of these companies eschew that kind of
notion. They say, "We pay our taxes, and that's funding you
guys." But, the idea was that it was mutually beneficial. They
would get information. And, the reason we were able to sell it
was, by 1979 Stanford biochemistry was one of the leading groups
in genetic engineering.

Hughes: Right, and that's what they wanted.

Berg: And that's what they wanted. Many of these companies were totally
in the dark about the developments. They were really grasping at
straws, and that's why there was momentum for small companies.
Guys who had ideas about what they could do with recombinant DNA
essentially didn't go to big companies, because [the companies]
didn't understand it.

Hughes: Were companies in the affiliates program less likely to start

there own recombinant DNA programs because they had a relationship
with you? Or was it an incentive?

Berg: It was more likely an incentive. The invitation to our affiliates
to attend our retreats where they actually heard about the ongoing
research didn't come until later. So, I can't cite that as
something that would have spurred them on. Because if they had
attended our retreats, they would have seen that all kinds of
exciting things were happening which they were not part of.

Hughes: You're talking about the departmental retreats at Asilomar?

Berg: Yes, that came later.

Hughes: Yes, I have an agenda somewhere.

137

Launching Biochemistry's IAP in the Late 1970s

Berg: We began to discuss an affiliates program in '78 or '79. By that
time, I think Bob Lehman was just coming to the end of his five
years as chairman. We were doing five-year terms. I stepped down
in '74. Bob Lehman would have done '74 to '79. So I suspect it
was right at the very end of his tenure that we began as a
department to become enthusiastic about doing this. And then Dale
Kaiser became chairman. And so it was during his tenure that the
program actually got underway.

Hughes: Why had members of the department become enthusiastic?

Berg: Well, probably two things. One is, given the notoriety of our
department, we were now more confident that we had something to
sell. Before, people were less confident, other than our general
renown, that we had anything to offer to commercial companies.

But, when it became clear that we were quite out front in
the area of genetic engineering, we felt we really had something
to sell, and it would be negligent perhaps to not take advantage
of that. We all made that same argument; we really could use the
money. I think we may have brought up what Chemistry was getting
out it. And having free, undesignated money; most grants
designated how the money was to be spent. We didn't have a bank
of free money. And so here was a way to accumulate money that
would guarantee security of the department.

I think everybody bought into it. I don't remember that
there was anybody who was opposed to it. And, as I say, we all
committed ourselves to that list of offerings that we were
prepared to do, and that meant [each faculty member] making an
effort to go visit one of the companies. Most people saw that it
was not a big deal because they were traveling a lot. So, on some
trip East, they could stop and visit company x, y, and z.

Increasing Commercialization of Academic Biology

Berg's Prior Refusal of Corporate Consultantships

Hughes: You at Stanford were prime scientific movers of recombinant DNA.
You must have been aware of people profiting from commercial
application of recombinant DNA technology. Was there motivation
to profit from it yourselves?

138

Berg: No, not at all. In fact--

Berg: --I had stayed away from any kind of consultantships, even though
many companies had come to me and asked me to be a consultant.
And, I think they had probably done that to Arthur as well. And
except for Arthur's connection with ALZA, which was largely
through his friendship with [Alejandro] Zaffaroni and whatever
other little companies Zaffaroni created, Arthur didn't have any
consultantships, as far as 1 know, with any other companies other
than those related to Zaffaroni.

I had a second reason for not accepting consultant
positions. I had been a central figure in the "ethics debate,"
the safety debate, and, given the public policy debate that was
going on in 1975, '76, '77, I thought I would lose my credibility
in terms of the position that I took if I was also involved in
some commercial enterprise.

It seems obvious that if you're working for a company, as I
see now, you have certain obligations or interests, and those can
easily influence and color your decisions about whether you think
some things are right or wrong, appropriate or inappropriate, and
so on. So I decided I did not want to do it. I was asked by Dave
Baltimore to join one or another commercial groups, but I chose
not to.

But, then I began to think a little differently about it,
although I didn't do anything commercial until 1980. Dave
Baltimore said, "Look, this field of genetic engineering is going
to blossom and is going to move ahead. If you participate in it,
you have a greater chance of influencing that it does it right and
properly and ethically than if you stay out of it." I agreed that
was a reasonable argument. But, nevertheless, I still said no to
most things.

Berg Reconsiders Corporate Connections

Berg: It was probably about that time that the whole DNAX [Research

Institute] concept got started, and we can go into detail about
that. But that was the first time that I at least conceded to
myself that this was an interesting proposition. Probably had it
not been Zaffaroni [making the proposal to found DNAX] , I would
have said, "No way." And had it not been in collaboration with

139

[DNAX co-founders] Arthur and Charlie Yanofsky, I would have said
no.

So it had a different flavor. Here were colleagues 1 really
respected, had worked well with, with the guy who was going to do
the business for us, who was a man I admired in many ways, and so
I finally said okay. So DNAX was the first time I conceded that
my stand-offish attitude was probably outlived. By that time, the
[biohazard] debate had more or less disappeared; in 1980 things
were blossoming.

The Recombinant DNA Controversy

Berg: In the summer of [1976] when the guidelines were issued, it was a
really hot debate. I was traveling around the country, meeting
with city councils and with university boards, trying to put a lid
on preemptive strikes at each of these places to foreclose the
possibility of doing recombinant DNA research, in the city of San
Diego, for example, or the University of Michigan campus. I was
involved in all these forums. So during that period, I felt it
was inappropriate to be involved in corporate ventures and didn't
get involved.

Herbert Boyer and Genentech

Berg: But I also defended the guys who did, particularly Herb Boyer. I
thought there was an opportunity to use the technology to do
something that would be medically significant, and if Herb wanted
to spend his time to do that, fine. The only thing I criticized
Herb Boyer on, and a number of other people at UCSF, was that for
a brief interval after they founded Genentech, they were doing
Genentech 's work at UCSF labs. I thought that was totally
inappropriate. And there was a whole lot of stuff about guys
taking their materials from refrigerators.1 There was talk of a

1 In 1999, Genentech and UCSF settled a case out of court regarding
use of biological material allegedly stemming from UCSF in Genentech
recearch on human growth hormone.

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kind of warfare that went on at UCSF amongst Bill Rutter, Boyer,
and their postdocs.1 That I thought was bad.

Hughes: Because it was so intimately mixed up with the academic?

Berg: That's right. Because they were doing work for their companies in
academic centers. That was totally inappropriate. But once the
Genentech labs got built, and they had a place to work off campus
and so on, I didn't have any problem with that. There was always
the possibility of a fuzziness in the boundary between what was
done at UCSF and what was being done at Genentech and how much was
passing from one place to the other. And, from the university's
point of view, they were losing "intellectual property" by people
essentially walking away with it.

Hughes: How did you feel about that part of it?

Berg: I spoke out against it. That's the only area on which I was
critical about the people who were moving in that direction.

Hughes: Do you have any opinion why UCSF happened to be so active in
technology transfer?

Berg: Well, Herb Boyer was clearly one of the leaders in the development
of the technology in the field and Bill Rutter was one of the
leading people in biochemistry.

Hughes: So, do I gather from that comment that it's more personality, more
individuals, rather than the institutional context?

Berg: Oh, yes.

Hughes: From what you have just told me today, Stanford might be seen as a
better locus for commercializing recombinant DNA because
interaction had been going on between industry and academia for
decades. Whereas, to my knowledge, there is not much of that at
UCSF prior to the recombinant work. So, it boils down to
individuals?

Berg: Oh, yes, there's no question. Herb Boyer being approached by

[Robert] Swanson was the catalyst. I don't know what went through
Herb's head in regard to why he wanted to do it. Either Swanson
was extremely persuasive, which he could be, or Herb wanted to get
involved with something to make money. And, I think Herb's

1 For coverage of this controversy, see: Stephen S. Hall, Invisible
Frontiers: The Race to Synthesize a Human Gene (Redmond, WA: Tempus Books,
1987).

childhood and background, a small town in Pennsylvania, is often
cited; becoming rich and famous was something that any young
American kid would aspire to. I don't know the reasons. But he
certainly has cited that.

This is just an aside, but if you look at what Herb has done
with his money, he has done some really tremendous things — gifts
to UCSF, to Yale, and so on. But, he also enjoys collecting
classic cars and has a big art collection. So he has enjoyed the
wealth, for sure, and used it well in many ways.

William J. Rutter

Berg: Bill Rutter was a very entrepreneurial guy right from the

beginning. 1 knew Bill when he was the treasurer of the American
Society of Biochemistry and I was the president of the society.
Bill was always into finance. He loved it. He was the link
between the society and the people who were investing its funds.
He was keeping track of our budget statements and how much money
it was costing us to run the journal. Bill was an
entrepreneurial, financially minded guy. He understood the stock
market. And, he was a good scientist. There is no question that
he did an unbelievably magnificent job of resurrecting
biochemistry at UCSF. 1 suspect that early on, he also saw
opportunities to apply what he knew.

Cetus Corporation

Berg: Cetus was another company that pre-existed recombinant DNA. It

was founded by Josh Lederberg and by Don Glaser. They also had a
very entrepreneurial businessman who probably drove that.

Hughes: Ronald Cape.

Berg: Yes. And we watched that. And at that time,1 there was no

recombinant DNA. What they were trying to do was use Glaser 's
skill at instrumentation to create a machine that could do very
rapid screening and isolate mutants that were more efficient in
producing antibiotics and various kinds of other activities. But

1 Cetus was founded in 1971, before the discovery of recombinant DNA
cloning technology.

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they had nothing to do with recombinant DNA at that point. But
when the recorabinant DNA thing came on, they quickly latched onto
it. They set up Stan Cohen here with Cetus Stanford, and created
something called Cetus Immune with Hugh McDevitt, 1 believe.

Hughes: Yes, and wasn't there an agricultural branch of Cetus?
Berg: In Madison.

They set up Stan here somewhere in Palo Alto, I think. I
don't recall where Cetus Immune was located. As near as I can
tell, they all failed.

Hughes: You don't know why?
Berg: I don't know why.

Hughes: Was Cetus one of the first companies founded to commercialize
biological knowledge?

Berg: Amgen got started after the introduction of recombinant DNA. So I
think Cetus is the first. Josh was still here as chairman of
genetics. I don't know of any other biology-based company. But
there may be.

Hughes: Syntex?

Berg: Syntex was a more traditional pharmaceutical company that moved
here from Mexico. Zaffaroni was not an academic. But Carl
Djerassi had worked at Syntex, and when he was recruited to come
to Stanford he maintained his connection with Syntex.

Hughes: Is Cetus really the first company founded by biological

scientists, not necessarily by people applying recombinant DNA?

Berg: Except for Syntex, I don't know of any other.

Hughes: Was it significant for the biotechnology industry that a company
in the Bay Area was making a go of applying biology in the
commercial world?

Berg: I don't remember that the creation of Cetus and its operation ever
elicited some kind of admiration or emulation. It was really
making use of Glaser's skill in gadgetry, in invention of
machines, because all they were doing was just mechanizing and
automating large-scale ways of looking at microbial colonies and
examining them in some clever way.

143

I remember Don Glaser came and gave a seminar and got a big
yawn. He was a very bright guy, very dynamic. But nobody that I
recall ever said, "Hey, that's the wave of the future."

Stanford's Policy on Consulting

Policy Reassessment, 1977

Hughes: Stanford had a faculty consulting policy which well predated the
recombinant controversy.

Berg: Oh, yes.

Hughes: But in March of 1977, President Richard W. Lyman delegated to the
Board of Trustees the task of establishing limits for consulting
activities.1 I can't tell you whether or not before that it was
university policy that faculty spend not more than one day a week
consulting. But certainly that came to be by 1977. Was the 1977
policy prompted by what was happening in the biological sciences,
or was this a more general problem at Stanford, not connected with
recombinant DNA?

Berg: I don't remember any problems, certainly not in the biological or
biomedical area. If there was any concern, my guess is that Lyman
would have been more concerned about the engineering school, which
had traditionally done a lot of consulting. There were also
people, for example, in the education field who were doing a lot
of consulting in various areas. 1 don't remember that there was
any specific event that instigated Lyman to do that.

Hughes: I'm glancing through the document and I don't see anything about
why Lyman 's concerned.

Berg: He says the policy contains some ambiguities. "It is in the best
interest of both the faculty and the University to clarify these
ambiguities. . ."2

Hughes: There must be something provoking him to reassesss the policy.

1 Lyman to members of the Academic Council, March 18, 1977 (Arthur
Kornberg papers, SC 359, Green Library, Stanford, box 5, folder: 1977).

2 Ibid.

144

Berg: Well, I think what happened, and maybe it happened around that

time. There was a guy at UC Davis-
Hughes: Ray Valentine?

Berg: Valentine, who helped set up a plant biotech company.
Hughes: Calgene.

Berg: Yes. There was a bit of a furor over the fact that Calgene gave
Valentine a research grant. He was one of the founders and the
principle officer in the company, and they gave him a grant to
carry on the research on the campus, that is, in a university lab.
That elicited a certain amount of eyebrow raising—was that
appropriate? My recollection is that there was a certain amount
of clucking that went on about that.

I think the University of California established a policy
which was that faculty could not accept grants from companies in
which they had a financial interest. And it may be that was one
of the things that stimulated Lyman. Maybe that was one of the
ambiguities. I don't have the chronologies-- When did Cetus
Immune, and when did Cetus Palo Alto get created? The question
was, was this a way of funding Stan Cohen's research, or Hugh
McDevitt's? I think there may have been a little bit of a concern
about this boundary between your own lab and the lab that you are
presumably directing for a company.

Hughes: Well, certainly, Donald Kennedy was very concerned, and even

testified in the House in 1981. He says in his testimony that
Stanford's faculty Committee on Research had voted overwhelmingly
to reject the university's equity participation in faculty
research ventures.1

Berg: I was one of the people that met with a group of venture capital
people, university people, and trustees to discuss this issue of
whether the university should in fact get into the business of
venture capital. Should it be using its funds to help faculty
found businesses? I argued vehemently against it. I wasn't the
only one. The venture capital people urged the university not to
do it, saying that the university didn't understand it; it would
be a disaster for them.

1 Statement of Dr. Donald Kennedy, President, Stanford University,
Stanford, California. Subcommitee on Investigation and Oversight,
Committee on Science and Technology, House of Representatives,
Commercialization of Academic Research, June 8 & 9, 1981, U.S. Government
Printing Office, pp. 6-28.

145

But, more important, we were more worried about the impact
on the academic setting. When the university is in business with
one of its faculty, what kinds of relationships does that create?
Does a guy get more money? Does a guy get favored promotions?
There were all kinds of things.

But, going back to '77, again without knowing the chronology
of when these companies were popping up around here. I don't know
of anybody else in 1977 who was doing any consulting. What did
get prominence was in fact that here we had on our campus or in
our vicinity two of our professors engaged in a company. Cetus
was already an existing company. If somebody felt there was going
to be some financial gain, the way to do it was to start a
spinoff, start something from scratch, so a person got in on the
ground floor for any financial rise. So, I think that was one
motivation for creating those two companies, or the three.

The third was to place new companies in the locale where
those people were doing their research, because they could easily
have said, "Look, 1 haven't got time to go over to the East Bay
and solve this problem," and so on and so forth. "But, if it's
right in my backyard, I would be left to run the operation." 1
suspect that is some of their motivation.

The Shooter Committee on Conflicts of Interest

Hughes: I saw a reference to the Shooter Committee.

Berg: I was on the Shooter Committee. The Shooter Committee was one set
up by the medical school.

Hughes: It's called the Shooter Committee on Conflicts of Interests. So,
you see there really is a lot of turmoil around this topic.

Berg: That's right. You have to recognize that the previous academic
environment was very permissive. Nobody kept track of anything.
Nobody knew what affiliations anybody had with companies. Nobody
checked on how much time they spent doing these things. So, it
was really an attempt to step back and say look, something is
happening; our faculty is becoming involved [commercially], and
have been involved, i.e. the engineering people and chemistry
people.

Maybe the fact that the University of California put a lid
on one area of involvement energized Stanford to look at the whole
problem. And so Lyman reiterated what he felt was the policy. It

146

wasn't that stringent. It said that you could consult for 20
percent of your time.

Hughes: One of the tensions was that the clinical people had to turn over
their consulting fees to the medical school. There was no control
of the nonclinical faculty, as you're saying; they just put the
consultant fee in their pocket; that was it.

Berg: That's right. Absolutely. Now, you're ringing a bell. Henry

Kaplan, who was head of radiology and was one of the most powerful
and influential figures in the medical school, was always griping
about the fact that clinical faculty could not accept fees or
anything of that sort. They were expected to be full-time, and as
full-time faculty, they were expected to turn over all earnings to
the medical school. And, I remember, as chairman of the
department, almost every executive committee meeting was Kaplan
pounding on that inequity. He kept identifying how inequitable it
was that basic scientists were beginning to develop these kinds of
consulting relationships and could keep their consultant fees.

I remember Kornberg made this argument, "We'll take your
salaries, and we'll give up our consulting fees. But if you
consider the disparity in our salaries, you can't be complaining
about that we're engaged in this kind of consulting activity."
So, that sort of kept a lid on it.

The Shooter Committee had to really look at the whole issue.
I was a participant in that committee. What was a conflict of
interest? A conflict of interest in my view arose if you have a
financial stake in some decision you're making, and you haven't
disclosed that you have a financial stake.

But the more critical thing from our point of view was what
I called conflict of obligation. In other words, you're a faculty
member here; you're expected to be here full time; you're being
paid a salary. You're here, and we expect you to provide the kind
of intellectual heat and creativity that makes this [university] a
great place. If your head is somewhere else, there is a conflict
of obligation. If you're thinking more about something you're
doing on the outside than what you are doing here, then you're
lost to us as a valuable person.

And so, we had to look at the whole issue of what was
conflict of interest, and that was easy. You could easily say you
have to declare any financial interest with anyone. If you're in
a position to order a piece of equipment, and you buy it from a
company in which you have a big financial stake, that's a conflict
of interest. But conflict of obligation was much more subtle.
For example, you're traveling around the country all the time

147

giving lectures, you're teaching courses at university X, or some
summer program, and you're not around here and you don't fulfill
your teaching responsibility here. That's academic; that's not in
any way a consultantship; that's not in this 20 percent time.

You serve on many boards ; you serve on many government
committees, but you're not around campus. So the question is, how
do we view that? How do we view a person who disappears from the
scene to write a book? Obviously, he gets financial rewards from
that book. What's different about that kind of activity than
somebody who goes off and consults for a company, gets paid by a
company?

Then, the second thing was, should we be snooping into how
much money people are getting for their consulting? The Shooter
Committee said that wasn't our business. But, we put in place a
reporting requirement, that is, every faculty member was required
to report what their outside activities involved and estimate how
much time they spent at them. And, we believed that by forcing
people to write down something, they would be lying if they did
more. I don't think anybody wanted to lie or disobey, but when
nobody asked, it was easy to just say, "Okay, it's a little bit
more this month than last month." But very quickly, you'd find
that somebody was spending a lot of time away. But we also set
down very clearly this whole concept of conflict of obligation. I
think that's now part of the lore that's used in terms of
evaluating.

Hughes: Well, how did you settle that conflict of obligation?

Berg: We just pointed out that this was an area in which we expected

individuals to fulfill their obligation to the university. They
were being paid full time to spend their time here and contribute
to the life and activities of the university.

I've had this conflict argument with other people; David
Baltimore and I have argued this. He probably spends 30-40
percent at MIT and 60-70 percent of his time elsewhere doing great
things. He said, "I am carrying the banner for MIT. By my being
on various committees and so on and so forth, I am representing
MIT and fulfilling an obligation to keep MIT at the forefront."
So, people had different perspectives on this.

Berg: Some believe that benefits accrue to the university from their

participation and consulting, bringing the outside world into the
ivory tower, knowing where the cutting edge is, what some of the
problems are, making opportunities available to their students.

148

Things like that. I mean, this 20 percent time has been justified
in many different ways, and it exists at Harvard, Yale, and MIT,
and most other [universities]. It was understood that consulting
was not to exceed a day a week, but nobody kept track, nobody
asked. I think most universities now require faculty to fill out
an accounting of whom they consult for and roughly how much time
they spend at it each year.

Hughes: And who sees those reports?

Berg: It goes to the dean. But, if you ask me does the dean ever look
at it; does somebody in the dean's office look at it? I don't
know. They keep it on record. I think it's there largely should
some abuse arise. Then someone can go back and say, "Look, you
said that this year you were not going to spend more time
[consulting]. Here, we now find out that you're involved in about
five things. You're the owner of a company, or you're co-founder
of a company, and you're spending a lot of time as a company
officer." So, it was largely there just to have a record, which
probably could be used when abused. But I don't think anybody
actually reviews these reports.

IV DNAX RESEARCH INSTITUTE OF MOLECULAR AND CELLULAR BIOLOGY,
INC.

Earlier Commercial Ventures

Hughes: In the second oral history that you did for MIT, which was with

Charlie Weiner, you said-
Berg: What year was that?

Hughes: 1978. You did an earlier one in 1975.
Berg: Yes.

Hughes: --that you didn't at that time want to be involved with a company.
I quote, "I have told at least four or five different companies
that I will not participate as a consultant."1 DNAX was founded
in 1980, right?

Berg: Yes.

Hughes: How did you get involved?

Berg: Well, I've read Arthur's recounting of the story.2 Both Charlie
Yanofsky, and I have a slightly different story. [laughter] And
it could be because we weren't aware of some of things that Arthur
was doing or saying. First of all, Arthur was a consultant; he
was actually a member of the board for ALZA. He was also a member
of the board for some little spin-off that ALZA created to try to
immobilize food dyes on various things, and that failed.

1 Paul Berg (second interview), April 17, 1978, p. 64. MIT Institute
Archives, Recombinant DNA Oral History Collection.

2 Arthur Kornberg. The Golden Helix: Inside Biotech Ventures.
Sausalito, California: University Science Books, 1995.

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Channing Robertson's Company

Berg: There was a guy named Channing Robertson who was the head of the

chemical engineering department. He had the idea that the biotech
industry was going to eventually want to produce products.
Everybody was cloning things, and they were trying to figure out
how to get them expressed. But, in the end, what had to be
produced, if it was going to be usable, had to be produced in
large quantities. And, being a chemical engineer, he was very
tuned into how you go about manufacturing chemicals .

What Robertson realized was that this was a whole new
ballgame because proteins were going to be the products of these
genes, and the chemical industry had not had any experience of how
to produce large quantities of proteins. So he had been
developing the kind of technology which allowed one to be able to
grow bacteria to very, very high densities, much higher than any
way you can grow them in a flask.

He could see that technology was going to be advantageous
since bacteria at that time semed to be the organisms that were
going to be producing these rare proteins. If you could grow them
to higher and higher quantities-- He, not being a biologist,
needed some help, and he came to see Kornberg. He also talked to
Charlie Yanofsky who was very experienced in growing bacteria.

Robertson told us about this notion he had of forming a
company, and that Stanford was in some way interested in becoming
a partner. Not bankrolling the whole thing, but in fact retaining
some kind of interest should this company do well. He went out to
a lot of chemical companies and raised a whole lot of money. I
don't think Stanford put any money into it, but Stanford retained
some form of interest which I just can't remember. He had a
venture capital firm here on Sand Hill Road, Palo Alto that would
be a principal investor. Robertson came to us and asked if we
would co-found this company with him.

Hughes: We being?

Berg: Kornberg, me, and Yanofsky. We were to be the scientific backing
for a venture into the next stage of genetic engineering. Instead
of doing it in test tubes, we were going to do it in factories.
And we said okay. This was about the time when I began to
reconsider my earlier objections to being involved in commercial
biotechnology. Zaffaroni was not even involved in this venture.

Hughes: Was this in 1980?

151

Berg: Probably the year before. Could have been '80, but I think '79

more likely. We thought it was kind of an interesting opportunity
and that Robertson had a fascinating idea for the kind of
technology he wanted to develop. He was the engineering expert.
And so we said okay. Then, we went to meet with the venture
capitalist to discuss what our stake would be in this company.

We were so sickened by our discussion with this guy that we
came out of there just saying, "Pretty slimy character." Although
he isn't a slimy character, I've learned since. But what they
were willing to give us in terms of stock options and blah, blah,
blah, seemed marginal. But, since we had never been involved in
this kind of business that wasn't so clear.

Alejandro Zaffaroni

Berg: So Arthur went to ask Alex Zaffaroni whether that was a fair deal.
That's my recollection. Arthur says he came to it in a very
different way. But I remember that Charlie and I thought of
asking Zaffaroni whether this was a conventional standard, fair
kind of grant. And Zaffaroni just laughed and thought it was
ridiculous and said, "If you guys are really serious about wanting
to get involved with a biotech company, I'll form one and you can
join me."

Alex then told Arthur and us that he had been approached and
had actually considered becoming an investor and a guiding light
for a biotech company that Harvard might start. He had been
approached and asked whether he would be interested. He had
consulted with Arthur about it—which may be, but certainly we
were unaware of that conversation- -but he said he turned them
down. When he realized that we were interested he began to
consider doing something with us.

I didn't really know Zaffaroni well, but I knew him through
Arthur, and I knew Arthur had the highest regard for him. He was
clearly a very innovative and creative entrepreneurial guy. He
said he would do all the business, and what he wanted us to do was
to provide the scientific energy behind forming this company.

Zaffaroni may have told us what our financial stake would be
if we started this company. It put the other one to shame. The
same attraction that had led the three of us to even consider
joining with Channing Robertson was there in thinking about DNAX,
except that now, with Zaffaroni, we had somebody whom we respected
and had confidence in. The Robertson company seemed more

152

ephemeral, although there was going to be a lot of other companies
involved along with the university. I don't remember that I
particularly thought that was bad because their stake was not
anything like what I had argued against before. It was a
different nature. Again, I don't remember the details.

Hughes: So you got out of the arrangement with Robertson?
Berg: We got out of it.
Hughes: Did anything happen?

Berg: We went to Channing and told him that we had this alternative

opportunity, and we were much more attracted to that. For one, it
got us into an area that was more closely related to our
interests, which was how to use recombinant DNA to make a
significant medical product, rather than commercial quantities of
proteins. Robertson's company was formed and went along for a
little while, and then it failed. I think the companies that were
interested from the beginning began to recognize that there were
other kinds of technology available to achieve the same ends,
whatever. But it eventually failed.

DNAX

Initial Research Focus, Recruitment, Science Advisors

Hughes: Had DNAX been refined any further than that? What were you hoping
to do with recombinant DNA technology?

Berg: Well, we had several brainstorming sessions. And we decided that
immunology would be the focus. Once we were engaged, Alex
Zaffaroni said, "I want to bring in a bunch of other people," one
of whom was a guy named Ed Haber, who just recently died. He was
a professor at Harvard. And then he engaged a bunch of people who
had been involved in ALZA, about five or six other people.

The first question was, who were going to be the scientists?
We were implored to try to convince some of our postdocs to join
DNAX. The first group we approached were postdocs, the first
being Kenichi Arai, from Arthur's lab. He had probably been
Arthur's best postdoc; he was a dynamo. But he had gone back to a
position in Japan but his wife, who was also a scientist, couldn't
have a position there. Arthur contacted him and said, "How would
you like to come back?" He did. There was a postdoc of Charlie

153

Yanof sky's, Gerard Zurowski, who had gone to Australia with a
Queen's Fellowship. He came back. Lee Hood, I think, was an
advisor. So he sent us one of his people, Kevin Moore, who is
still at DNAX.

Hughes: It was an impressive group of advisors.

Berg: This is typical of Alex Zaffaroni; you engage a lot of big names,
to impress potential investors and for recruiters. But a lot of
the advisors contributed very little.

Ed Haber and the Engineering of Monoclonal Antibodies

Berg: The interesting thing was that Ed Haber was a cardiologist at

Harvard. One of the drugs that he pointed out was very useful,
was Digoxin. Older people, he said, frequently overdose on
digoxin. They forget that they just took their pill and they take
another. Or, some kids eat grandpa's pills and they go into coma.
What he had done in order to treat people like this was to develop
a monoclonal antibody, which he was using to inject into such
people with remarkable results; like within twenty minutes to a
half an hour, they would be out of the comatose state, get off the
bed, and go home.

Hughes: Where would he have found the monoclonal antibody?

Berg: He made it. He was an immunologist by training, a very good one.
But he was a cardiologist by profession. So he made a monoclonal
antibody against Digoxin by attaching Digoxin to an inert carrier.
You inject the carrier and then you screen for antibodies that are
directed against the chemical entity to which you attach it. You
remove all the antibodies that are to the inert carrier, and then
you get antibodies very specific against Digoxin. And then, you
try to get one that has a very high affinity for it.

What Haber found was that he could clear the body of Digoxin
by just injecting the monoclonal antibody. Antibodies come with
two kinds of chains, heavy and light chains. He claimed that you
could take the Digoxin antibody apart and it would reassemble. I
think he also had shown that you could make what they call an Fab
fragment, which is a fragment of the antibody but it contains the
combining sites. Fab fragments have all the same kind of
specificity and affinity for these ligands, antigens. But they're
much smaller and they are secreted or excreted very rapidly.

154

Haber had shown that the Fab fragments were even more
efficient in being able to sop up the digoxin. They gained entry
into places that the big proteins can't go. They're smaller bits;
they go in and attach and eventually are excreted. So, we thought
we could synthesize the heavy and light chains in bacteria by
isolating the genes that encode the heavy and light chain
proteins. And, since he had these cells that were making this
monoclonal antibody, we could isolate the cDNAs from them and
engineer them so that we could make heavy and light chains in £_._
coli. And, the heavy and light chains could be prepared in large
quantities, then we could reconstitute the active antibody.

We knew it wasn't possible to engineer the structure of the
antibody combining site directly, but we could change the
structure of the gene at will. And we could make antibodies with
very different kinds of specific affinities. So, the concept had
emerged- -Zaffaroni gave it a name, but I can't remember the name
of it. But you could imagine that you could start making
antibodies that would be used in the chemical industry for
extracting things. You could make antibodies specific to
anything. You could use them like a first-aid kit. You can
imagine, for every kind of toxic substance that somebody could
ingest there could be a monoclonal antibody that would be injected
into a person to neutralize the toxic agent.

Hughes: How far along was the technology? How grounded in actual science
were all these ideas?

Berg: We knew you could make cDNAs . We had these brainstonning

sessions. We sat around the table and said, "Okay, our first
target ought to be to use genetic engineering to make specific
antibodies, or parts of antibodies, engineered in ways to give
them special properties, which could be used in a variety of
commercial and industrial and medical uses."

Utilizing the Okay ama -Berg Procedure

Berg: Now, my lab had just worked out a technique for being able to make
full-length cDNAs. The earlier work that had been done by Tom
Maniatis said made it possible to make cDNAs but they were rarely
full-length, full-length meaning that they contained the entire
protein coding sequence.

Hughes: Would that be Okayama?

155

Berg: Yes. The Okayama-Berg procedure was designed to guarantee that

you got full-length cDNAs, even if they were very big genes. And
so I said, "We have a technique for being able to use Haber's
cells, extract the RNA from them and make full-length cDNAs that
would encode the heavy and light chains." Charlie Yanofsky was
the world's expert on regulating expression of genes in E. coli.
We could then engineer these coding sequences into E. coli and
make large quantities of heavy and light chains. Then, we would
extract these heavy and light chains, purify them, then put them
together, and then reform the antibody.

Hughes: Was it somewhat fortuitous that you three had major facets of the
problem to contribute? Is that why you were involved initially in
DNAX?

Berg: When we agreed with Zaffaroni, there was no clear plan of what we
were going to do. Therefore, our individual expertise, other than
being in a general area of molecular biology and molecular
genetics, was not evident. It was Ed Haber who brought this as a
possibility and said there was a market for these kinds of things.
Then we began to say, well, how would we make antibodies? Well,
the only way to make antibodies that I knew was to actually clone
the genes. But not the genes because the genes are much more
complicated to work with. Clone the cDNAs, express them in £_._
coli ; Charlie knew how to do that. Arthur was sort of not
involved because he wasn't an expert in any of these areas. But
we did adopt the Okayama-Berg method as the principle approach to
do this.

Okayama being Japanese sometimes writes English a little
more like Japanese. And so, the method that was published was
actually quite difficult for most people to follow because it was
quite intricate. Again, like the first creation of the first
recombinant, it required a lot of experience with enzymes and
dealing with them in different ways. Most of the enzymes we had
in-house .

Hughes: So, you had a corner on the market?
Berg: That's right.

Problems in Engineering Monoclonals

Berg: Kenichi Arai came from Japan. He immediately consulted with

Okayama, and before you knew it, these guys at DNAX were cranking
out clones with no problem. It turned out, they made heavy and

156

light chains, but they would not reassociate. Ed Haber had shown
that he could reassociate heavy and light chains for other
antibodies, but not this one. So here we'd gone through this
entire exercise and everything worked perfectly; full-length cDNAs
were being expressed in E. coli. But, they would not reassociate.
We tried to make it so that both genes were being expressed in the
same cell, and maybe they would reassociate under those
conditions. We never could make a functional antibody.

Money was running out. Alex had raised some $4.5 million to
get DNAX started. We didn't have more than about ten or twelve
scientists working and we had used up all of this money.

Fundraising

Hughes: I know Arthur was involved in some fundraising trips.

Berg: Oh, yes.

Hughes: Were you as well?

Berg: I went on one fundraising trip with Alex to New York, where we met
with the people from the Rothchild venture capital company. It
was based in New Jersey. Alex and I met with their group of
scientific advisors; tried to get them to invest. Sydney Brenner
was their consultant. He put us at the top of the heap in terms
of scientific expertise and prominence. He thought DNAX was a
great, great idea, and so on and so forth. But, they never bit.
In fact, it was one of the greatest disappointments I ever had.
We never even got a response from them. We met with them, we took
them to dinner, and we had this fancy talk. I thought we
convinced them and that they were going to buy it. [laughter]
But, we never even got a reply.

Hughes: Do you think they understood the science?

Berg: Oh, yes, they understood the science. Arthur, I think, met with
somebody from Rothchild 's on one of his trips to England. We
never could find out why it didn't go. But, in any case, Arthur
and Alex made several trips to Japan where Arthur had all kinds of
contacts. A former postdoc of his, Omura, was a major figure for
Takeda Chemical. So DNAX was on the verge of going under.

157
Schering-Plough and DNAX

Schering-Plough 's Research History

Berg: I think Alex went to Schering-Plough because the new management of
Schering-Plough were people that he had known from Ciba-Geigy.
Ciba-Geigy had been, essentially, the owner of ALZA; they bought
ALZA from him. And so he went to see them to tell them about
DNAX. And there was the almost extraordinarily fortuitous
circumstance that they were looking for new directions. The
company had been at its nadir in terms of successful products.
They'd had a very successful antibiotic, which was going off
patent. Their prospects were zilch; they had nothing in the
pipeline. And, they had, during the year 1978- '79, conducted a
strategic survey of what were the promising directions to go in in
the future. And, they chose immunology.

To implement this new strategy in immunology, they created a
laboratory in Lyons, France, largely because they were obliged to
by the French government in order to protect their pricing
capabilities. So they built a lab there and said this is where
we're going to do immunology. And when they went out to try and
recruit people to do it, they were really unsuccessful.
Everything that they tried to bring immunologists into their
research organization had failed, in part because their reputation
was pretty lousy for research.

So when Zaffaroni presented them with the existence of a
company committed to immunology, and they saw the board, and they
saw the scientific advisors, and they saw that there was a team of
scientists on board, they began to see that if they just acquired
DNAX, they would have an instant presence in the field of
immunology research. And so, after a few discussions, I went East
with Alex to make a presentation to the scientific board of
Schering. We thought they were just going to make an investment,
keep DNAX separate. But then Alex came back and said their
proposal was to acquire the whole thing. And, I can tell you
there was a lot of discussion and resistance.

People thought that we had committed to building something,
creating something special. We had this sense of ownership, and
suddenly we were selling out. But, Alex was astute and recognized
that in fact all the value that DNAX had would grow. Because, if
Schering Plough and its fortunes were down, and they ended up, we
would all benefit from that. So, we bought into it.

158
Scientists' Initial Reluctance

Hughes: What about the effect of the poor image research in the
pharmaceutical industry had in the academic world?

Berg: Oh, there's no question that existed. That was part of the thing.
We didn't respect their science. Frankly, not many of us even
knew anything about their science. We didn't know that they had
not been a very successful pharmaceutical company in generating
research, in generating products. They were just some big enemy
out there, part of the pharmaceutical industry which none of us
had a lot respect for.

But, I think the principle thing is, or at least my
recollection is, we felt like we were selling out, that we had
started this [company] with a grand idea that we were going to
create the next Syntex, or something like that. We had
established certain criteria that DNAX had to meet: we had to
have a very academic environment, that people were free to
publish, that people would be able to talk about their work. All
the kinds of things that were anti-traditional to pharmaceutical
company style, we were rejecting. And, we said DNAX is going to
be an open environment--

Berg: --so that the scientist would not become invisible to the academic
community and they would be able to move freely back into
academia. If you were successful, you would be known. You would
be publishing and so on. So, we were very concerned that through
this acquisition, all of what we promised these people and the
kind of style we were hoping to achieve would be lost, and that
Schering would not honor that goal. But Alex, I think, was hugely
successful in persuading them to leave DNAX as an independent
research institute, to live by the parameters we had created for
its lifestyle, culture, and everything that we had told people was
going to continue.

Hughes: If he had not been successful, do you think you would have stuck
with it?

Berg: Well, I think one would have had to see just how offensive it
could have become.

159
J. Allan Waitz, DNAX President and CEO

Berg: In fact, we came very close to rejecting the arrangement, because
once the deal had been consummated, we were sent a person from
Schering-Plough to become the president. We thought, this was the
beginning of the end; here was a guy who was going to instill his
culture, their culture on us. But it turned out, he was totally
swept away by the way we were, and Al Waitz became the great
champion to the point of offending his Schering-Plough colleagues
and masters by how he defended our way of life, and the way we
were doing it, and what we were doing, and so on.

Hughes: I remember from Arthur's book the comment someone at Schering-
Plough made to Dr. Waitz, "Are you working for them or for us?"1
[laughter]

Berg: Al was terrific. He really got caught up in California, and our
style, and the way we worked. He had a lot of influence at
Schering-Plough, because he had been a leader in their interferon
project. He had worked with the CEO, [Robert P.] Luciano, and so
Luciano respected his views. Al protected us against a lot of
other people.

Tensions between DNAX and Schering-Plough

Berg: As you might imagine, there was a lot of jealousy because we were
allowed to work in one way on the things we wanted, and people
there were required to work on company projects. And then, the
quality of the science in the two places was a mismatch. I mean,
there's no question, Schering-Plough was the pits, and people we
had at DNAX were leading people. When DNAX reported what they
were doing or tried to get collaborations going, they lost respect
for the people at Schering-Plough. DNAX scientists didn't think
Schering-Plough scientists were quite up to being able to follow
them. So I think in the beginning there was a lot of tension.

Hughes: Another source of tension, I should think, would have been

Schering-Plough' s rather ambivalent, or maybe even negative,
experience with Biogen. Remember that?

1 Arthur Kornberg. The Golden Helix; Inside Biotech Ventures. Sausalito,
CA: University Science Books, 1995.

160

Berg: Yes. Their financial deal was, they made an investment in Biogen,
and in return they got the complete license for the use of alpha
interferon. That was what they bought; they bought a product. In
order to buy a product, they had to make their investment. I
think they had a 10 percent ownership. Al Waitz was on their
board. Hugh d'Andrade was on their board. I don't think
Schering-Plough was disillusioned with Biogen until quite a bit
later. And in the end, they got a big financial return. Not only
do they have a product which today is a three-to-four-hundred-
million-dollar-a-year product, but in addition, their investment
in the ownership of stock went up. So they did quite well.

But the DNAX thing was really more of a strategic

investment, that is, if they had decided that immunology was going
to be the core of their research program, and the entree into
infectious disease, cancer, and things of that sort, they needed a
strong core.

Hughes: Who were the main competitors in that area? Presumably other
pharmaceutical companies had also targeted immunology?

Berg: Oh, yes. I think immunology was seen as a central player. I

don't know who else staked their strategic future to the extent
that Schering did. Big companies probably didn't have to. But,
Schering-Plough was really groping. They didn't have anything,
and the market knew that .

Hughes: Well, as you know, once the Schering-Plough acquisition occurred,
there was a shift in the research agenda.

Berg: Yes.

Hughes: Would you like to talk about those decisions?

Berg: It's twelve o'clock.

Hughes: Oh, that's what that means?

Berg: Yes, my little beeper beeps.

Hughes: It tells you when you're hungry? [laughter]

Berg: No, it's there because this watch has to have an alarm setting.

And so I conveniently put it at noon because I'm up. If I put it
at seven o'clock in the morning, I don't want to wake up. So, I
had to find some time [to program it to], and it always evokes
some comment, "Oh, is that my time up," or something like that.
But actually, I booked us for lunch, like I did last time,
[interruption]

161

Maxine Singer was invited to the meeting that we had at MIT
where we drafted the "moratorium", or "Berg", letter. But she was
taking her kids to Disney World in Florida and decided that was
more important than being at that meeting. But when we came out
with that letter and were planning to have the Asilomar meeting, I
certainly her to be a participant on the organizing committee.

Her husband, Dan, was at the Asilomar meeting and was very
influential. As the history goes, the lawyers opened our eyes to
our collective responsibility, obligation, and vulnerability to
being sued, and so on and so forth. Dan was the one who organized
the discussion that evening by the lawyers and helped to identify
the people to invite, all of whom were very influential in the
outcome.

ALZA and DNAX

Hughes: I have a news release of March, 1981,' which was before Schering-
Plough acquired DNAX the next year. Zaffaroni announced that
DNAX's strategy was "unique in combining three technologies-
genetic engineering, immunobiology , and drug delivery systems."
Now, the drug delivery systems was a Zaffaroni connection, was it
not?

Berg: Well, one of the investors in DNAX was ALZA; $600,000 worth, 1
think, out of the $4.5 million that bankrolled the company.
Zaffaroni's vision was that we could make proteins through genetic
engineering, and that ALZA was going to develop delivery devices
for delivering proteins. Remember, delivering proteins across
membranes is not a trivial job. And, all of the delivery devices
that they had made until then were delivering small molecules.

He foresaw that if you made therapeutic proteins, delivering
them at known sites, known rates of release would be important.
And so ALZA was supposed to be part of this kind of consortium
that would design delivery devices for proteins. They still
haven't done it. Delivering proteins is still a big, big
challenge.

1 [News release], March 9, 1981. (Papers in the possession of Arthur
Kornberg concerning DNAX and his book The Golden Helix. "Helix" carton)

162
DNAX's Original Product Goal

Berg: The whole thing that we were focused on was how to use the
recombinant DNA technique to actually make designed
immunoglobulins with very special properties. We talked about
being able to make enormous columns, if you will, of protein
molecules, mobilized on supports through which you could pour
crude mining extracts. And they would extract the gold, or they
would extract some very, very low abundance material because
antibodies have an incredibly high affinity. And you could use
genetic engineering to modify the combining sites of natural
proteins to increase their binding specifity and so on. Alex
actually got a patent. It was for high-affinity binding sites, or
something like that. I forget what it was called.

[perusing documents] Dynapol was the other company [of
Zaffaroni's] that Arthur was involved with. It was a spin-off
from ALZA.

Hughes: Is that the company you were referring to?

Berg: Yes. I think Arthur says he lost his shirt on that. [laughter]

One of the important things that emerged after the
acquisition, which really helped delay some of our fears about
what was going to happen, was that DNAX was to be governed by a
policy board. The policy board was to have me, Charlie, Arthur,
Zaffaroni, and three representatives from Schering-Plough, and
that balanced how things were to be decided. These policy board
meetings would be held here in Palo Alto. Like a board of
directors of a company, it would act as a board of directors for
this common joint venture, and that, again, helped make us feel
that Schering-Plough was willing to make concessions. Then, there
were reassuring statements about East is East and West is West,
and we're not going to try to blend the two. The personnel
policies were different for DNAX than they were for Schering-
Plough employees. So they clearly recognized that there was
something special about DNAX and it had to be nurtured.

I shouldn't say they realized. They were taught, totally
encouraged to believe that. [laughter] At every meeting,
Zaffaroni, Arthur, and I would beat on them about the very special
quality of DNAX and the risk of losing it. In fact, I remember
when Alex was trying to talk us into going for this merger, he
said, "What have you guys got to risk? Let's assume that they
come in here and they transform DNAX into Schering-Plough West.
You guys leave, what have they bought? They bought you. That's
what the value is. There's no product; there's no anything; they

163

bought you. So in order to make their investment worthwhile, they
have to enlist your compliance." And we realized that was true.

The Shift to T-cells

Hughes: There was a shift in research direction after the Schering-Plough
acquisition. It was not going to be antibodies, but interleukins .

Berg: Well, what happened is in this strategic review they had, the part
of immunology which Schering-Plough got sold on was T-cells.

Hughes: Who was pushing T-cells?

Berg: This was a guy named Harvey Cantor, who was a professor at
Harvard, who was a good immunologist. He had been on this
strategic advisory board, and he had persuaded them and the rest
of the people that T-cells were the crux of the immune system, as
it was understood in 1980. They are the cells that sense antigen
first, and they elicit the rest of the immune response by
secreting cytokines, interleukins as you call them. He had
already done some studies to show that a certain cell line, when
stimulated, produced all kinds of cytokines.

So when Schering discussed the acquisition of DNAX, they
said they were not interested in antibody production; they were
not interested in making these mickey mouse little things that
could be injected to cure overdosing on Digoxin. They would be
interested if we would work on T-cells. Nobody felt totally
wedded to the antibody project. That was always viewed as being
just to get us in the door, just to get the company started.

Hughes: Not much research on antibodies was already done?

Berg: It had been going along for a bit. It clearly wasn't succeeding,
and we probably would have been confronted with making some new
choices. But when they said T-cells in trying to identify these
cytokines, it was clear we could translate the same technology,
that is, cloning cDNAs. Within an instant, Kenichi Arai and those
guys took the cell lines from Harvey Cantor and started cloning
out cDNAs for all kinds of things.

164

The Expression Vector Technique

Berg: One of the major things they had adopted was a technique Okayama
and I developed called an expression vector. Expression vector
means that when you clone the cDNA into the vector, it's already
in place to be expressed to make the protein. Whereas with normal
cloning, you just clone it into a plasmid. After you've cloned it
you try to recognize it by its sequence. But if you don't know
anything about the gene sequence, and you're looking for a gene
that makes a kind of protein that has a biological activity, you
want a system where you make the proteins in the cloning
operation. We had developed this expression cloning system, and
that was probably the single most important contribution to the
success of DNAX. DNAX cloned all kinds of cytokines.

Hughes: DNAX had this expression system when other companies did not?

Berg: Other companies did not. But very quickly others recognized that
that was the way to go. So they developed variants, all of which
had the same capability so that when you cloned the sequence, it
was in a position behind the promoter so it could be expressed in
animal cells or in any system you wanted.

The company Genetics Institute developed an expression
system; actually it was a postdoc, Steve XX [Berg can't recall the
full name] from my lab who had been there when Okayama developed
the expression cloning system, who then went to Genetics Institute
and developed a comparable promoter using adenovirus. We were
using plasmid systems. Essentially, it took advantage of the fact
that you could clone full-length cDNAs, and when they're cloned,
they're put into a vector that expresses them. So DNAX was a new
gene a month. I mean, it was really booming because it had
developed a very good way of cloning rare things that had never
been known before.

Recruitment of Scientists

Hughes: Whom did DNAX recruit?

Berg: There was the core group: Kenichi Arai because he came back from
Japan, Gerard Zurowski came back from Australia, Kevin Moore from
Lee Hood's lab, a few others. DNAX tried to recruit Okayama,
because he was a whiz . But he came from a Japanese background
where he thought he would be unlikely to ever ^et a job in
academia if he went into industry.

165

Hughes: It probably would have been true at that time, would it not?

Berg: At that time, it might have been true. Today, it's not at all

true. Kenichi Arai went back as the professor of biochemistry in
the Institute for Science and Technology at Tokyo University, and
Okayama went from being the professor in Osaka to Tokyo
University.

Hughes: It sounds, from the way you've just described it, that the way
these people came to DNAX was largely through personal
connections .

Berg: That's right. And a lot of selling—selling in the terms that

this was going to be a congenial, exciting, productive environment
that would be every bit as academic as any academic position would
be. They would be paid well and have a stake in the future of the
company, and they were free to publish and talk about their stuff.

Research Freedom

Hughes: Also, and this really surprised me, DNAX scientists were given the
opportunity to pursue their own research.

Berg: That's right. Within certain bounds. Somebody wanting to work on
photosynthesis would not come to DNAX.

Hughes: There was somebody at DNAX working on photosynthesis.
Berg: There was, and Gerard had been doing it before.

Everybody was assured that they had a certain fraction of
time, 20, 30, 40 percent of the time, that they could do whatever
they wanted. And their other research was to relate to the
principle theme of DNAX. But the principle theme was very broad.
It was molecular immunology and subsequently became molecular
immunology and cell growth control. Within those boundaries,
people could do almost anything.

Gerard Zurowski, who was working in Australia, was doing
some plant work. He came here and carried on the plant work for a
while . But he got so caught up in the immunology part of it and
the plant work eventually went by the wayside, and that happened
for most people. The work was so exciting and successful that
most people got drawn into it and left behind whatever thing they
had in mind before.

166

Hughes: I spoke of the cloning gold rush. I saw some memos that stated
that after a few years, there was a lull at DNAX and other
companies rushed in and actually took the plums.1 What was your
feeling at that point?

Berg: Well, my recollection is, the first plateau was all these

cytokines were being mined successfully by Immunex, which is
another company, and Genetics Institute. There were a number of
times that we won, a number of times they won. That is, they got
to the goal first even though we were all competing for the same
thing .

Cloning Cytokine Receptors

Berg: But then we came to the realization that the next big direction
was to understand the receptors to which these cytokines bind.
The way cytokines act is they bind to receptors that are on the
cell, and then there is a signal transduction; something gets
passed on to the nucleus, which then triggers the cell to do
something to respond to that signal. What we began to realize is
that just knowing the first part of it, what are the things that
you put out as hormones, wasn't enough; we had to understand how
the cell responded to those hormones, those signals. That's the
crux of the immune response.

So, we had to pursue new goals. One of those new goals was
to start cloning the receptors specifically for these cytokines,
and ultimately to understand the pathway by which a signal
transmitted from the receptor to the nucleus. And that, today,
constitutes the principle mission of DNAX. What DNAX had as an
edge was a very special skill in isolating and focusing on the
rare cells of the immune system. In other words, you could take
T-cells, but then there are subclasses and subclasses, and there
are different kinds of B-cells at various stages. And all of them
have unique patterns of gene expression. So if you can begin to
enrich for certain cell types, you have access to certain kinds of
proteins that somebody looking at the bulk won't ever find. And
so that has been the DNAX's expertise.

Today DNAX is moving along working with cell types which
probably very few people in the world know how to isolate, grow,
and adapt. DNAX is looking for gene discovery in those cells

1 For example, see: J.A. Waitz to Policy Board Members, December 29,
1986. (Arthur Kornberg personal papers, DNAX 1987-1988 [sic])

167

under the assumption that if you identify the important protein in
that system you might have an edge into a particular function,
maybe a disease, and so on.

A Long Discovery Phase

Hughes: Arthur in his book writes about the congeniality between the

people at DNAX and Schering-Plough. But I nonetheless suspect
that there were some tensions. Did people like Luciano, the top
guys, appreciate how long it would take from the discovery phase
to an actual product?

Berg: They did. They told us right in the beginning that they did not
expect to see any products from DNAX research for probably the
order of ten to twelve years.

Hughes: How could they have known that?

Berg: If you take a strategic view to the pharmaceutical industry, you
have to think long-term. It takes a long time from even the most
promising discovery in the lab until you get something you can
sell. And many things fall by the wayside. So they knew the
game.

Hughes: From past experience.

Berg: Yes. I think what they were trying to do was to take the pressure
off us. They wanted us to do cutting-edge research. They wanted
us to be at the very frontier of this field, with the confidence
that it was going to lead to commercial value. And they didn't
want us to feel that we had to prove tomorrow that we had made
something.

DNAX Benefits Schering-Plough

Berg: But in point of fact, within a very short time, Schering-Plough
had patents on a lot of very valuable stuff.

Hughes: But an actual product wasn't on the market until about 1990.

Berg: That's right. But Schering knew that they had things in the
pipeline that were potentially very valuable. But more
importantly, they also recognized that DNAX scientists had made an

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incredible reputation and inroads in the field of immunology.
They were now looked upon as leaders of the field. And for an
organization that had a bad image in the research field, DNAX was
a jewel in their crown. I mean, they could boast that the number
of papers published, number of symposium speakers, and by almost
every criterion, DNAX was one of the leading research places in
immunology.

DNAX had made several discoveries, which while they didn't
have commercial rank, had radically transformed the field of
immunology. I mean, the whole idea that there are two classes of
T-helper cells, each secreting unique sets of cytokines was a
bombshell. And to this day, DNAX is cited as the place where
these discoveries occurred. Today, DNAX scientists are considered
amongst the leading ones in the world.

Hughes: How did Schering-Plough commercialize this very prominent research
group that they had on the West Coast? How did it help them sell
their products?

Berg: Well, I don't think it helped them sell their products. There are
two, I call them, intangibles.

Berg: There's no question that today Schering-Plough in New Jersey is a
first rank research organization, whereas when DNAX first joined
them, it was pitiful. So there has been a transformation in their
research organization.

Hughes: How did that happen?

Berg: Well, in large part because they recognized the disparity; that
things coming from DNAX couldn't be implemented at Schering-
Plough. People at Schering didn't fully understand them.

Hughes: So Schering began to attract better scientists?

Berg: Yes, with our help. We helped recruit people. We have been very
active in Schering-Plough' s activities, in recruiting leadership
in various positions. They don't hire anybody in the science
organization unless we approve it.

Hughes: Is that by contract or is that just an understanding?

Berg: I'll call it dependence. And recognition. Recognition of what we
contribute. Nobody is hired at DNAX without each of us having
interviewed them. I mean, Arthur, Charlie, and me. We've done a
lot of active recruiting, that is, persuading people who are on

169

the fence about whether they want to go to academia or go to
industry.

The second point is, DNAX had been incredibly efficient in
generating new kinds of cell cultures, which then could be used
for assaying special kinds of things. These were very valuable,
and all of these were transferred to Schering. So Schering got
technology, got materials, potential drugs, some of which are
still in clinical trial, and a turnover in their own
establishment. So, they've been transformed. And I think they
rightly give DNAX a lot of credit for having catalyzed it, aided
it. You could say, well, the way commercial companies judge value
is not always the way we judge it. We think of it in terms of
big, big accomplishments. But the transformation of a nearly
moribund scientific organization on which a pharmaceutical company
has to depend into one which is now recognized and can recruit
very easily is an important accomplishment.

Second, their investment looks very good because, for not a
lot of money, about $28 million at the time of the acquisition,
they bought a world-class research organization. And they got a
lot of--. Which word do I want?

Hughes: Kudos?

Berg: Yes. --for having done it. In fact, Arthur wrote this book

[Golden Helix] because he was told that DNAX was used as a case
study in business schools. People said, gee, somebody ought to
write this all down.

Arrival at Stanford. 1959
Advance Preparation

Hughes: In our first interview, you said that you wanted to talk, and we
did not, about your earliest experiences at Stanford,
[interruption]

Berg: You have enough material about how we got recruited to come to
Stanford.

Hughes: Yes, I agree.

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Berg: So we had two years lead time to prepare for it, and that two

years was one of active designing the building in which we were
going to move, its interior wasn't yet designed, and preparing for
what we hoped was going to be a totally novel way of teaching
biochemistry. Remember that the group that moved here from
Washington University were technically all microbiologists; we
were in the microbiology department. We considered ourselves all
biochemists, and in some ways we were parading under false
pretenses .

Hughes: Standards.

Berg: The move here was looked to going to do something really novel and
exciting in biochemistry. During those two years we helped
develop a teaching program that was really remarkable and lasted
for at least five to eight years in terms of being the most
popular course at the medical school.

An Unfinished Science Building

Berg: In June of 1959, we were supposed to come here from St. Louis and
move into the new building. When we got here, the building wasn't
completed. We were told that it was on the way, and we should
just wait. So we camped out, in a sense. We had a hut where the
secretary sat who came with us. And we would come in every day
and say, "Any news? Any news?" And, we would hear, "No, they
haven't done anything."

So, eventually, we got so frustrated that Arthur, who had a
lot of clout, went to the administration and said he was outraged,
furious, and so on and so forth. And so what they did was gather
all the workmen that were working all over the medical center, in
the hospital and everyone out there, onto the third floor of the
medical school building. And they finished us up in a very short
period of time.

We had these moving vans that had transported all our lab
equipment and supplies, and we moved right in. We moved in
probably by sometime in July, and by the middle of August
everybody was doing experiments.

171

Settling In

Hughes: And teaching?

Berg: We started teaching again in September. We had a new course. We
were all teaching in new areas. But the research was going on.
We had every barrel, every box marked, ticketed almost exactly to
which drawer everything was supposed to go in. We had worked very
hard to sterilize and wrap all the stuff we wanted to take. When
we came, we had a carpenter; he built the dividers and drawers.
It went from the barrel right into the drawer.

The only glitch we had was that there were a lot of air
vents and things built in, and we couldn't get certain instruments
onto the table because these things were sticking out. So we
unscrewed them and capped them. But the building had never been
officially tested. They put pressure on all the air lines or the
gas lines to see that they don't leak. Well, of course, they
leaked like a sieve because, what we had put in was not standard,
[laughter] So we got the fire department down our back. There
was a little flap.

Hughes: They knew that biochemists were in town. [laughter]

Berg: Yes, and working very quickly. It was really an amazing move.

Hughes: You had been orchestrating it for almost two years from St. Louis,
from what you said.

Berg: Everything was planned down to a T. We brought with us

secretaries, technicians, students, even shop people. And so we
had everybody ready to transform the floor into a working unit.

The Stanford Department of Genetics

Lederberg's Arrival at Stanford

Hughes: I got the impression from going through the archive that a

collaboration or a partnership, whatever you want to call it, with
the Department of Genetics headed by Lederberg was really on
people's minds. And yet, from what I can tell, it did not really
materialize. Am I right?

172

Berg: Yes, to a certain extent. Josh Lederberg was in the field of

genetics, probably one of the shining bright stars. He had been
invited to come to Stanford and turned it down. But when Kornberg
and we accepted to come, I think it might have been Kornberg who
contacted him and said, "Think again. We're coming, and I think
that between your genetics and our biochemistry, we can really be
a powerhouse." And Josh changed his mind.

Now, unfortunately, when Josh changed his mind, there was no
space, because there hadn't been any program to have a genetics
department. So we gave him space in our department.

Hughes: There had been no genetics department?

Berg: There had been no genetics department. In fact, I think Stanford
was the first medical school to actually create a genetics
department .

Hughes: Is that so?
Berg: Yes, 1959.

Hughes: So, it was the Department of Genetics in the Department of
Biochemistry?

Berg: Well, it was the Department of Genetics autonomous in every way.
But the space that they used was in biochemistry space.

Stanley Cohen's Associations with the Biochemistry
Department

Hughes: Because Genetics and Biochemistry were in more or less the same
place, it was easy for people like Stan Cohen and Sgaramella to
participate in biochemistry seminars. Is that right?

Berg: That's right. Only Stan never was really located in that space,
because when Stan came to Stanford in 1968 he was in the
Department of Medicine. He was recruited to become the director
of the Division of Clinical Pharmacology. So he had space
somewhere else.

I knew him before because he came from a lab of one of my
closest friends, Jerry Hurwitz at Albert Einstein College of
Medicine. I knew about Stan and when he came, I certainly had an
open feeling for him. He then hit on plasmids as the thing to
study in the area of drug resistance, which was clinical

173

pharmacology. When we found that the enzyme EcoRl would make
cohesive ends, and Mort Mandel discovered how to incorporate DNA
into cells by giving them calcium shock. Stan started hanging out
in Biochemistry because he saw that we were working now with
plasmids. My student Janet Mertz was doing all these experiments,
and she taught Stan how to do these transformations.

Hughes: So, up until then, he hadn't been around very much?

Berg: No, not at all. Walter Bodmer, who is now a distinguished

professor of genetics at Oxford, interacted a good deal with our
department. He and Josh formed the core of the genetics
department. They had some postdocs, one of whom went on to become
the head of the Eliza Hall Institute, Gus Nossal. Nossal, Bodmer
and Leonard Hertzenberg were on our floor.

Lederberg and Space Biology

Berg: Josh was somewhat aloof and had very little to do with the

research. In fact, at that time Josh was involved with planetary
biology. He was learning about rockets and space biology and so
on. So he really tuned out.

Hughes: Was that soon after he arrived?

Berg: Yes, because I remember, in 1961 I went to the International

Congress of Biochemistry in Moscow. Josh was already actively
involved in space biology because he enlisted me to sit in for him
at this meeting in Moscow with other space biologists. I didn't
know anything about it. But anyway, he was very heavy into it.

Josh told me, he denies it today, but I remember very
clearly. He used to come walking by my lab on his way out,
because his office was what became my office when I became
chairman. He was on my corridor. He often would stop in with his
arms full of books on planets, cosmology, astronomy, and rockets.
He would come back the next morning with the same books already
digested. He was remarkable.

Anyway, he said that he left what he had been doing before
in genetics, in part because he realized-- The structure of DNA
was published in 1953. From '53 to '59, Josh was skeptical of the
notion that DNA could explain the gene's properties. He argued
that genetics couldn't be explained by this molecule; there were
too many complicating features about genetics that couldn't be
explained by this simple molecular structure. Josh, I th:.nk, was

174

one of the last hold-outs, but by the time he came to Stanford, he
was convince that it was correct. Nevertheless, I think Josh
recognized that he was out of it because he was never molecularly
oriented; he was largely a classical geneticist. And now genetics
had become molecular, and he wasn't into it. Walter Bodmer, along
with Ganesan, a student of Josh's, was doing transformation;
Nossal was doing immunology, and Josh had to find something new.
Space biology was sort of blossoming as a possibility, and he just
went right for that. Josh says today that he doesn't remember
ever saying that. But I remember very clearly because I was
really astonished to see how somebody who was as extraordinary as
he is eventually felt that he had been eclipsed.

Faculty and Tenor of the Genetics Department

Hughes: What about the other people in Genetics? Was there much
interchange with Biochemistry?

Berg: No. There was Indian fellow named Ganesan. He was a graduate
student, and he worked with Bodmer on DNA transformation. Josh
brought Luca Cavalli-Sforza, who was a human geneticist, to
Stanford. A wonderful man who had had a strong history in
microbial genetics but now had gone into human genetics.

It was an interesting culture. Josh's department was very
different than Biochemistry. Biochemistry was extremely
interactive. Josh's department was, you're on your own.
Everybody was on their own. There were very few faculty meetings
It was a non-department. Josh was involved in traveling around
the globe doing his things. People were doing their own things.

Minimal Interaction between Biochemistry and Genetics

Berg: I think Arthur would probably say, and I would too, that a
coalescence between Genetics and Biochemistry never really
happened. It didn't happen in the teaching; it didn't happen in
research. There was virtually no collaborations that were
established. And there was no real intellectual interactions. We
knew them and we knew what they were doing. I think the closest
it came was when Stan started coming up to the department to
interact, with Mort Mandel, who was a visitor in Dale Kaiser's
lab, and with my graduate student, Janet Mertz.

Hughes: How about Sgaramella?

Berg: Sgaramella was also a postdoc in genetics. He had come from

Khorana's lab. He came to my group meetings, and I'm sure he came
to biochemistry department seminars, but I don't remember that as
well. But I never saw him as a strong element or a strong part of
the genetics department. He was a transient, who had already come
with a problem. I mean, the problem that he worked on in
Khorana's lab was this discovery that T4 ligase would join blunt-
ended molecules. He certainly came to our group meetings and he
participated in the discussions. I'm sure he must have given a
presentation of his own work, but I don't remember it.

Biochemistry's Policy on Joint Appointments

Hughes: So it wasn't a rich exchange back and forth?

Berg: No. But you also have to remember that Biochemistry was somewhat
aloof. Biochemistry itself was quite snooty; it didn't interact
with anybody. It had a policy: it would not offer joint
appointments to anybody, whereas lots of other places would help
in the recruitment of a person for one department by giving them a
joint appointment.

When I was chairman of the department [1969-1974], I sat on
several committees that were trying to create a cancer center.
The notion was that there would be some new building, and people
would be in that building but have their appointments in various
departments. I literally torpedoed those kinds of ideas because
Biochemistry would never allow any of its faculty to be in other
than Biochemistry space.

Hughes: As chairman, you could have led a crusade to change the policy.

Berg: Yes, but I believed in it. Actually, there was one other person
in Genetics who was really terrific, and that was Eric Shooter.
Eric Shooter came to our department as a postdoc; he was already a
pretty senior guy. But he came on sabbatical to work with
Baldwin. And then he went back to England. Then Josh got a gift
from the Kennedy Foundation to create a neuroscience program. He
recruited Eric Shooter to come back and head up this neuroscience
center. So Eric was given a joint appointment in Biochemistry.

Hughes: He was the first in Biochemistry?

176

Berg: I can't remember. I think he was the first significant one. He
was located in the genetics department. The genetics department
and Biochemistry were separated by a swinging door. One of our
graduate students elected to work with Eric Shooter. Within six
months, he asked to be reassigned to somebody in Biochemistry. He
found being isolated uncomfortable. He was mixed in with postdocs
from Eric Shooter's lab, and they were doing genetics. He didn't
feel part of the genetics department. I think that convinced most
of us that those kinds of things don't work. If you have a
faculty member in another building, and he has graduate students,
those graduate students don't become part of the culture of the
main department. So we resisted giving joint appointments. In
fact, it was only about two years ago that we actually had the
next such appointment, it was Gilbert Lhu, who had been a postdoc
in my lab .

Hughes: Since 1959? That's amazing.

Berg: Well, actually, the Shooter joint appointment was probably in the
mid-sixties .

Interdisciplinarity

UCSF

Hughes: I'm thinking of the very different model at UCSF, at least as it's
been portrayed to me, in which departmental lines are quite
porous. The Program in Biological Sciences [PIBS] is totally
interdisciplinary .

Berg: But you're talking about now. That wasn't the way it was in the
sixties .

Hughes: That's true.

Berg: PIBS was almost the last five years.

Hughes: Is it that recent?

Berg: That's right. Mike Bishop was one of the creators of PIBS.

Hughes: The idea of a much less departmentally oriented effort began to
evolve at UCSF in the 1970s.

Berg: I would place it more in the eighties. I'll t.ell you why.

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A Consolidated Stanford Graduate Admissions Policy in
Biology

Berg: There was a sense that Stanford biochemistry as a department was
beginning to compete for graduate students with places that
offered more variety and opportunity for graduate students. While
we had been extraordinarily successful in recruiting graduate
students, we were beginning to lose out to places like MIT, UCSF,
Caltech that were now creating larger entities into which students
could enter and then select where they wanted to specialize.
Whereas we had a very restricted set of options. We had only ten
faculty.

Hughes: And you did biochemistry. [laughter]

Berg: That's right. And we didn't offer opportunities to somebody who
said, "I'd like to come to Biochemistry but I want to do cell
biology." So that was one of the impetuses for CMGM [Center for
Molecular and Genetic Medicine]; that's the whole thing. I tried
to get the department to agree that we would have a schoolwide
admissions process, not identified as biochem. Until two years
ago, Biochemistry said, "We don't want any part of any kind of
bigger departmental thing. We'll only diminish the quality of the
students we get. We'll have to compete with other departments.
Other departments will either admit people that they think are
good enough but they're not our type."

So I started a program for admissions in CMGM which was to
run in parallel, because I knew there was no way that I could
eliminate the biochemistry program or its admissions process. So
I started our own. We started one under the center's auspices
which brought in students and allowed them to remain
undif ferentiated, uncommitted for a year. They could go to any
department in the medical school.

Hughes: Has that been successful?

Berg: It has now become the program under which our graduate students
are admitted. Jim Spudich, who is the current chairman, finally
began to recognize that in the program that Stanford had every
department was going through their own process, reviewing
applications. It made more sense to lump together all the
"biology" at Stanford, offer a program that admits a student to
Stanford biology, and then give them a year to decide where to do
their Ph.D. research. Some go to biology, some go to
biochemistry, some go to pharmacology, some go to genetics, and
that's much more efficient. Last year, we got a terrific group of
students .

178

The thing that was going on at UCSF was a very strong
interest. As we began to learn of the development of the PIBS
program, we could see that what was happening was we were having
to compete with people who could offer students a much richer
environment.

Beckman Center Programs

Hughes: These interdisciplinary programs also reflect what's happening in
science. So you have to train people in an interdisciplinary way.

Berg: Yes, so at the Beckman Center, we retained the departmental

structure, because I think it's the most efficient administrative
unit. And probably for creating a kind of social structure that
interacts and creates loyalties, it's good. Overlaying that, we
have created a whole series of interdisciplinary,
interdepartmental programs focused around themes.

We have one that is called Cell Sciences. So it brings
people from Developmental Biology, Biochemistry, Pharmacology,
Genetics. They all have an interest in the structure of a cell
and how it's organized, what are the skeletal elements, how do
things get shunted around. We have another one in immunology;
again, it brought together people with very different backgrounds,
including clinical departments, including people over on the
campus --biology.

Now we have four such programs . We have one in human
genetics, one in immunology, one in cell sciences. We are now in
the midst of trying to create one called structural biology.
Because, just for the reason you say, the problems have become so
immense, that no one individual can bring to bear the kind of
insights, the technical expertise, or the knowledge to be able to
attack that problem in a comprehensive way. So what you have to
do is bring people together.

The whole idea is to create groupings that meet together,
talk together, get a grant together, have retreats. So I use
funding that I get from the Beckman Foundation to seed these
programs. And sometimes I have to do it by seduction, like the
cell sciences program. People were saying we didn't have good
microscopy, and cell biologists really need good up-to-date
microscopy. I said, okay, I will create a superb microscopy
facility, state of the art, if you guys will put together a
program that will build the intellectual activities around it. So
we have a terrific facility. We expend $100,000 a year to

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maintain it, but people are now doing advanced kinds of microscopy
that they've never done before. We have the same thing for
molecular structure. We have twelve computers sitting in a
facility which is now dedicated to teaching people to do molecular
modeling. So you begin to get people who talk to each other.

So the department lines now have become what I like to call
very permeable. People and ideas go across departments easily.
But structurally it's still Biochemistry, still Genetics, and so
on. It took a while to get my colleagues to accept that, Arthur
being one of the most resistant to the--

Berg: --Beckman Center concept. But I think today he has a very
different view of it. I think he sees it as valuable.

Beckman Center for Molecular and Genetic Medicine
Origin of the Concept

Berg: To get to how the CMGM came about: During the recombinant DNA

controversy, many of us who were participants were saying that to
justify going ahead with something that might be slightly risky we
need to consider all the benefits and rewards that would come from
it. And most of those, we forecasted, were going to be in
medicine. Some predicted it would be in agriculture, but most
thought it was medicine that was going to be impacted the most.

I had a visit from a professor of medicine here, Kenneth
Melman. He said, "You go around talking about all these things
that are going to happen in medicine. I don't have anybody in my
department who even understands the words . So if you think that
we're going to translate these great things that you guys are
doing into practical medical benefits, you have another guess
coming. That was a sobering thought, because I always thought our
Department of Medicine was pretty good. But they were of a
different vintage. And the field was exploding.

So Ken Melman and I began to meet with the dean and we said
what we really need to do is to create a new entity at Stanford
which is composed of people who are trained in medicine but have
elected to do science. Examples of such a breed were Mike Bishop,
Harold Varmus, Mike Brown, Joe Goldstein. These are people who,
following medical school, and clinical training, got intensive

180

basic science training and elected to follow a career in basic
science instead of clinical medicine. But they always have in
mind the nature of the biological problems, the medical problems.

One could foresee that if you got these people organized in
some way, you could have very easy transfer of new information,
new discoveries, new technologies, to the "clinic". In other
words, you want to have a group of people who can speak to both
physicians and the scientists and have the respect of both; I
dubbed it the bench to the bedside activity.

We sold that bill to the medical school and the university.
The idea was to create a department of eight new faculty, all to
be newly recruited. We had identified a group of people, many of
whom came out of M.D.-Ph.D. programs, who were looking for just
this kind of an opportunity to bridge across the two fields. But
there was no space to house them. There was zero space. The
medical center was filled.

By the time we got around to thinking about building a
building, we realized that we had other needs for space as well.
For example, developmental biology was exploding. So why
shouldn't we have a Department of Developmental Biology? We had a
Department of Physiology which had become moribund, literally.
Physiology was being taught to the medical students by physicians
who weren't at the cutting edge. And so we argued that we should
create a new kind of department which was dubbed Molecular and
Cellular Physiology. The departments were Molecular and
Developmental Biology, Molecular and Cellular Physiology and
Molecular and Genetic Medicine. Those names were not accidental
choices; they were all chosen to drive home that molecular was the
level we wanted to understand things at.

Raising Funds

Berg: Well, once we decided to have three departments, it was clear we
would need big money and a big building. The Howard Hughes
Medical Institute was then headed by Don Fredrickson, who had been
the former director of the NIH, and who on his own had been trying
to promote this kind of training in people. Physicians who do
science. When he heard that we were going to do that, Howard
Hughes offered us $12.5 million towards creating this kind of a
center. The Howard Hughes ultimately added another $7.5 million,
for a total of $20 million. They adopted the Department of
Molecular and Genetic Medicine and called it the Howard Hughes
Institute Unit of Molecular and Genetic Medicine. HHMI doesn't

181

have departments. They also agreed to fund twelve investigators,
plus the $20 million towards the construction.

Actually, I got a little of the chronology wrong. There was
a steering committee created to try to develop this concept.
Besides me there was the dean, Dominick Purpura, Stanley Cohen,
Hugh McDevitt, and Ken Melmon, the head of medicine at that time.
We brainstormed and focused on having a center for molecular and
genetic medicine.

At that time, Arnold Beckman had let it be known that he
wanted to give away his fortune before he died, and that he would
entertain proposals for new projects. We put together a proposal;
we invited him to come; he spent three days; we outlined our
vision; he went away; we never heard from him again. We only
found out later why.

In the interim, I proposed that we have an annual symposium
called the Symposium on Molecular and Genetic Medicine. We
couldn't build a building without money; we didn't have any
people, but we ought to at least start promoting the term, the
concept, on a national scale. So we had several terrific national
symposia on this theme. Fredrickson came to one of them, and we
told him our plans. He was going to become the president of the
Howard Hughes Medical Institute and he would recommend investing
$12.5 million in the CMGM and ultimately more. So we had a start
on the funding. But no word from Beckman at all.

We had $12.5 million; the building was going to cost
something like $40 million, and because we were so far short of
the cost the trustees would not allow us to move ahead, either to
plan or do anything. But Beckman remained silent. Only later did
we learn that he was not about to fund a project under the aegis
of a "directorate", our steering committee. He felt, "That's not
the kind of organization I want to support. I want to see one
person who has committed his energy, vision and activity
full-time, and whom I believe and trust. I won't give money to
something that is going to be run by a group." With no word from
Beckman, the project was moribund. At that point Don Kennedy came
to me and he said, "Either you become the director, or we drop the
whole thing."

I had been asked several times to be the director. I had
refused; I didn't want to do that. I was perfectly willing to
spend time on this committee developing the concept. But I did
not want to be the lead. But when Kennedy threatened to trash the
whole project, I agreed.

182

Within weeks, I called Arnold Beckman and I said, "There has
been a change in our plans. I have become the director. I'd like
to come to talk to you about my vision for what will happen. And,
he invited me to come. I asked Don and Arthur to join me. We met
with Arnold Beckman for twenty minutes. And two weeks later he
called and said he'd give us the twelve and a half million dollars
we asked him for. Later, when the big announcement about his gift
was made, he was asked why he was making this gift considering
that he had no affiliation with Stanford. He said he knew me; he
knew Arthur; and that he had complete confidence in us. If I was
willing to take the responsibility of directing this whole effort,
then that was good enough for him.

Hughes: Quite a compliment.

Berg: It was. So now we had thirty some odd million dollars, and then
Arnold Beckman helped us raise some money from other sources,
which he had access to. He persuaded SmithKline Beecham, then
SmithKline Beckman, to give us $8 million dollars. It's rare that
an industrial company gives you money to build a building. So we
got the Center built.

Berg's Strategic Decisions

Berg: There were several strategic decisions which I had to make, which
in retrospect I believe were the right ones. I should have said
before: When I was asked to become director, I said I had two
conditions. One was that the school would allow the building
planning and construction to go ahead even if we didn't have all
the money in hand. Kennedy agreed to that. And second,
biochemistry had to become part of the center. I said there was
no way I was going to devote the next five or ten years of my life
and leave my colleagues sitting in the old building in antiquated
space. Well, it wasn't quite antiquated, but they had to be part
of the center. I also believed that there would be an enormous
drawing card for recognition of the center if the famous
biochemistry department was going to be in it. That meant the
building had to be bigger and cost more money. The cost was going
to be up around $50 to $60 million. So the job of fund raising
came to be a big job. But we raised almost $96 million in those
three years. I spent a lot of time on the road, meeting with
people, persuading them. Dave Kern was very important and Arnold
helped as well. But, eventually we got the money to go ahead.

Another strategic decision was the three new departments in
that building, besides Biochemistry, were to be comprised of

183

people who were recruited from outside, not who were already ar
Stanford in existing departments. There were two reasons for this
decision: you could gather up all the stars that existed in
Stanford departments and move them to the Center and leave behind
a wasteland. That was the worst thing you could have done because
it would have really created a lot of anger and anxieties. Those
ransacked departments would now have had to go out and recruit
replacements.

We had the advantage in being able to do that. We had a new
building; we had a terrific concept. So I said we were not going
to move any people. And Stan Cohen became my bitter enemy, in
part because he was on that steering committee. I recall once
when I came back from a trip to find that Stan had carved out
space for himself in that building, as had Melmon and a few other
people. When I came back I raised hell. When I became director,
I said, "There are not going to be any moves." Obviously, I was
vulnerable because I had insisted that Biochemistry would move to
the Center.

Hughes: How did you handle that?

Berg: I said straight off that that was my price for being Director. I
had made it clear that I was not going to do it without
benefitting my colleagues who I was convinced would enhance the
standing of the Center and thereby aid in the recruiting of new
people. I think that was correct, indeed Arnold Beckman agreed.

Hughes: The other departments were created de novo?

Berg: Yes. So we set about recruiting. Eventually, we had to give in a
little on the decision of nobody from Stanford. The building was
going to take two and a half years to build. Howard Hughes had
committed money and positions, and they kept saying to us, "Who
are the Howard Hughes investigators?" Well, you couldn't recruit
anybody to a building that was not going to be available for two
and a half years. So we eventually identified a few people within
the school who almost surely would have been Howard Hughes
investigators anywhere else. The three of them were Jerry
Crabtree, Irving Weissman and Gary Schodnick. That's all we did.
They became the founders of the Howard Hughes unit, which
ultimately reached twelve people. So everyone else was newly
recruited- -new chairmen, and new faculty.

To this day, I'm absolutely convinced my decision was right
because had we filled the Center with the people we had, we never
would have been able to create the kinds of connections back to
the departments. The whole idea was to use the Beckman Center as
the focus for this concept of molecular genetic medicine and build

184

bridges to existing people. So we recruited people who could
relate to or connect to the strength we already had, and that
happened.

The second important decision came from the recognition that
there was a political problem. There were a lot of people who
wanted to be in the Beckman Center, new space. We frequently
heard, "I do molecular genetic medicine; why shouldn't I be in
that building?" We had to admit, "We all do molecular genetic
medicine. "

The Program in Molecular and Genetic Medicine

Berg: It turns out there are a hundred and ninety people who do what

could be called molecular and genetic medicine. We can't all be
in one building. Instead, we can be part of and intellectual
group called the Program in Molecular and Genetic Medicine [PMGM] .
Members of PMGM differ one from another in where we live. In
terms of funding, access to facilities, teaching opportunities,
you name it, everybody has equal access, and that's what we have.
In a sense the Program in Molecular and Genetic Medicine serves as
an umbrella for those interested in molecular and genetic
approaches to biological questions.

The physical focus is the Center. The Program encompasses
people in the basic science departments, the clinical departments,
chemistry, biology, applied physics. There are now 196 people who
declare themselves as members of the program. They are invited to
all kinds of PMGM functions. They've organized these
interdisciplinary units on various themes. They have their own
retreats seminar programs. We try constantly to meld basic
science with clinical activities. We have workshops where we have
brought physicians in to tell us about bone marrow transplants; we
have immunologists and gene therapists who want to use bone marrow
transplants.

It has been an exciting enterprise. When I retired from my
professorship in 1998 the dean said, "I want you to remain as the
director of Beckman." Actually, I don't direct anything other
than to try to create new kinds of interactions. One has to be
clever and imaginative to get people to come together when they're
all busy doing their own thing.

185

Stanford Biochemistry's Asilomar Conferences

Berg: The Asilomar conference was my invention when I became chairman of
the biochemistry department. We needed a way to get people in the
department to talk to each other about their research. We used to
do it in the department library but people were sneaking out to
the lab or going home early. It was clear that the only way it
would work was to go away from Stanford and its distractions. We
started the Asilomar conferences in 1970 or '71, and they've been
running ever since, not always at Asilomar. Now it's the
highlight of the scientific year.

Hughes: Who goes?

Berg: Everybody; there were 175 people that went to the Stanford Center
at Fallen Leaf Lake at this last one. I just got back last week.
Every group is given a slot of time, usually 60-90 minutes, for
presentations. The head of the research group programs what the
people in his group will present. There is a lot of time for
discussion. Those that don't get a chance to talk about their
work, do it through poster sessions. Most people feel it's the
best scientific meeting they've attended in the year, because
there is terrific research going on. It lasts three days, and is
intensive, nose-to-nose. People eat every meal together. That
format has been copied all over the country. UCSF has started it;
Berkeley has started it; Harvard, MIT. They all have retreats;
they all have found local places where you can go and hide.

Hughes: Stanford's was the first?
Berg: We were the first.

Greatest Contribution

Hughes: I have one more question, but is there anything you want to say
before that?

Berg: No.

Hughes: What do you consider to be your greatest contribution?

Berg: Some years ago there was a celebration of Severe Ochoa's

seventieth birthday, in Spain, and all of his former students,
colleagues and friends were invited to go. I think Arthur was one
of the co-organizers. I was not a student of Ochoa; I had never

186

had any collaboration with Ochoa. But for some reason early on he
took a liking to me, and he always treated me like one of his
"children", so I was invited to go to Spain for this symposium.

We were each asked to write an essay. Most people just
wrote a paper about some of their recent work. I tried to do
something different. I tried to ask what is the measure of
somebody's greatness or the contribution they made. What meant
the most to me is the long-term impact of ones work or efforts.
Pebbles dropped in water produce a succession of ripples, and one
might ask what those ripples created. Is it just the impact of
the stone, or is it the effect of the ripples that's important? I
tried to think of it in terms of who have these people trained?
Who are the people who have brought their style, their message,
their philosophy, their whole concept of science and taught their
students that way.

I had the idea of trying to measure this by way of a star
chart. An individual would be represented as a dot. The people
that person trained would be represented by radiating lines from
that dot. The length of the line was to be proportional to the
impact or success that person had achieved; that would be a
measure of his or her accomplishment. Then those people would
have trained somebody, and there would have been branches off that
line. You would have created a halo around this dot. The density
of the halo would be a measure of what the person had contributed
to science, and how far the halo came would be some measure of how
successful his progeny were in science.

I tried to do that kind of representation. Ochoa was one,
and I was going to have about five or six other heroes in science
to get a measure of their impact. Some of them have done great
science and got the Nobel Prize but hardly ever trained anybody,
or ended up with flunkies who never went on to do anything else.
I wanted to be able to illustrate that, but Arthur talked me out
of doing it. He said, "You will make enemies that will last a
long time. How are you going to be able to identify who this line
is, and who the short stub is?" I thought better of it, and I
didn't do it. But the concept has always stuck in my mind.

When you ask me what has been my greatest contribution, I
think it's the students that have come out my lab, and the
tremendous science that many of them have done, and the affection
ad relationship that exist between us. I'm still in touch with so
many of these students. They put on a party for me on my sixty-
fifth birthday, which would blow you away. The party took over
the Mark Hopkins Hotel, and the DeYoung Museum. The museum has a
magnificent hall hung with tapestries, which served for the
dinner. The organizers, all students, raised $160,000 for this

187

party. Former students and postdocs came from Europe, Asia, all
over the world. It was an incredible party. Anyway, that
relationship and admiring what they've accomplished to me is the
most important thing.

Many of them say that the way we did science in the lab at
Stanford has always influenced the way they do science and what
they try to convey to their students. To me, that is probably
more than just the few things that I've done, or done with them,
because that radiating effect is going to influence much more of
science than I could have done alone.

I think about our department in the same way. Our
department has done a lot of great science; It's not possible to
talk about contemporary science without running into someone who
was a postdoc or student at Stanford. That's a very satisfying
feeling.

Hughes: Thank you.

Transcribed by Quandra McGrue
Final Typed by Grace Robinson

188
TAPE GUIDE--Paul Berg

Interview 1: July 15, 1997

Tape 1, Side A 1

Tape 1, Side B 11

Tape 2, Side A 22

Tape 2, Side B 31

Tape 3, Side A 40
Tape 3, Side B not recorded

Interview 2: August 12, 1997

Tape 4, Side A 42

Tape 4, Side B 51

Tape 5, Side A 61

Tape 5, Side B 71
Tape 6, Side A not noted (only 5 minutes recorded)
Tape 6, Side B not recorded

Interview 3: September 30, 1997

Tape 7, Side A 80

Tape 7, Side B 90

Tape 8, Side A 100

Tape 8, Side B 110

Tape 9, Side A 120
Tape 9, Side B not recorded

Interview 4: November 5, 1997

Tape 10, Side A 128

Tape 10, Side B 138

Tape 11, Side A 147

Tape 11, Side B 158

Tape 12, Side A 168

Tape 12, Side B 179

SAMPLE EDITED PAGE
189

(from transcript, with

narrator's editing)
141

molecule, and, inside the cell, it jjuutfjlHLLwLy circularizes and the

TV
nicks mi muuuuh. between the ends get closed. And new it functions

as a circular DNA molecule.

Creating Artificial Cohesive Ends

Berg: So, the concept of sticky ends wpe already tteste . If you want to
join two different molecules together, it doesn't take

genius to figure out that if you can &e*w«41y create artificial

frlA \~Tr4t t+ I* j
ends that are complementary to each other Cftttt the two will come

A
together. Right? No big deal.

So, th* q\igf7ti"n in. if ynn ha"? a paggp vf TW ft nrH yn

have. OV40 DMA D, if you put tails of A1 on ••e' and tails of T on

j^ f\

-e J
••e'

rhni'.nfthrr,. and jpi: mix them, the A's and T's will form double

J*W J> *-***>
helices, and the two molecules will come together. Tw^s cannot

<?f
join to itself ^TJssPcould have used G's and C's, but A's and T's

were easier to add.

We already knew how to add tails onto tifewEe DNA molecules

because there is an enzyme that had been described which is

,.*-

present in flfc calf thymus ' a«*d has an interesting physiological

f unction, but ftR; was^ not known at «wt time. It w*6 DNA

t' >
polymerase, but "K*6 a dumb DNA polymerase. It doesn't need a

5 Tr,

template. If you give it any one of the four deoxynucleo^idef/^ it

"p< K * *)* j-k '±4.
will add Jt£ on to the end of the DNA molecule jfd JU-UICESSEB. So, if

. -
r DNA molecule A, and--jfi>i put in deoxyATP and this

*^S. POy -v»f i , **

enzyme, it wiil pfel^naerrpc A's onto the two 3/prime ends of this

DNA. And if you do it with deoxyTTP

in ill: "lull T's -oar. By regulating the time

the reaction, you

APPENDIX

A Paul Berg, CV and Publications 190

B Selections from Berg papers, courtesy Green Library,

Stanford University 208

C "The 1980 Nobel Prize in Chemistry," Science, vol. 210, 21

November 1980 241

190 APPENDIX A

PAUL BERG

Professor of Biochemistry

Stanford University School of Medicine

Stanford, California 94305

Bom: June 30, 1926, New York, New York

Address: 838 Santa Fe, Stanford. CA 94305
Soc. Sec. #: 095-18-1653

Education:

1948 B.S., Pennsylvania State University

1952 Ph.D., Western Reserve University

Professional Background:

1950-52 Predoctoral Research Fellow, National Institutes of Health.

1952-54 Postdoctoral Research Fellow, American Cancer Society, Dr. H. M.

Kalckar, Institute of Cytophysiology, Copenhagen, Denmark and Dr.

Arthur Kornberg, Washington University School of Medicine, St. Louis, MO
1954 Scholar in Cancer Research, American Cancer Society, Department of

Microbiology, Washington University School of Medicine.
1 955-59 Assistant to Associate Professor of Microbiology, Washington University

School of Medicine
1959-60 Associate Professor of Biochemistry, Stanford University School of

Medicine
1960 Professor, Department of Biochemistry, Stanford University School of

Medicine.
1969-74 Chairman, Department of Biochemistry, Stanford University School of

Medicine

1970-94 Sam, Lulu and Jack Willson Professor of Biochemistry.

1973-83 Non-Resident Fellow of Salk Institute.

1985 Director, Beckman Center for Molecular and Genetic Medicine.

1994 Named Vivian K. and Robert W. Cahill Professor in Cancer Research

Honors:

Eli Lilly Award in Biochemistry (1959)

California Scientist of the Year (1963)

National Academy of Sciences (1966)

American Academy of Arts and Sciences (1966)

Henry J. Kaiser Award for Excellence in Teaching at Stanford University School of

Medicine (1969, 1972)

Distinguished Alumnus Award, Pennsylvania State University
V.D. Mattia Prize of the Roche Institute for Molecular Biology
Institute of Medicine, National Academy of Science (1974)
President, American Society of Biological Chemists (1975)
Honorary Doctor of Science, University of Rochester and Yale (1978)
Sarasota Medical Awards for Achievement and Excellence (1979)
Annual Award of the Gairdner Foundation (1980)
Nobel Award in Chemistry (1980)
Albert Lasker Basic Medical Research Award (1980)
New York Academy of Sciences Award (1980)
Foreign Member, French Academy of Sciences (1981)
American Association for the Advancement of Science Scientific Freedom and

Responsibility Award (1982)

191

National Medal of Science (1983)

American Philosophical Society (1983)

Associate Member of EMBO (1984)

Honorary Doctor of Science, Washington University, St. Louis (1986)

National Library of Medicine Medal (1986)

American Academy of Achievement (1988)

Honorary Doctor of Science, Oregon State University (1989)

Special Achievement Award, Odyssey Biomedical Corporation

Fellow of American Association for the Advancement of Science (1991)

Honorary Member of the Academy of Natural Sciences of the Russian Federal Republic

(1991)

Foreign Member of the Royal Society (1992)
Fellow, American Academy of Microbiology (1992)
Honorary Member Alpha Omega Alpha Honor Medical Society (1992)
Honorary Member AMBO/AMBL (1994)

Honorary Doctor of Science, Pennsylvania State University (1995).
Member, Pontifical Academy of Sciences (1996)

Special Appointments:

Editor, Biochemical and Biophysical Research Communications

Member, NIH Study Section on Physiological Chemistry

Member, Journal of Molecular Biology Editorial Board

Member, Board of Scientific Advisors of Jane Coffin Childs Foundation for Medical

Research
Member, Advisory Boards to National Institutes of Health, American Cancer Society,

National Science Foundation, Massachusetts Institute of Technology, and Harvard

University
Elected to the Council of National Academy of Science and to the Scientific Advisory

Board of the Welch Foundation
Member and Chairman, International Advisory Board of the Basel Institute of

Immunology

Chairman, Whitehead Institute Board of Advisory Scientists
Chairman, National Advisory Committee, Human Genome Project
Trustee, Rockefeller University

Chairman, Board of Directors, National Foundation for Biomedical Research
Chairman, Public Policy Committee, American Society for Cell Biology
Advisory Editorial Board, Molecular Medicine Today
Advisory Panel, Human Genome Education Program
Whitehead Institute Board of Associates
Scientific Advisory Committee, Research! America
International Scientific Advisory Board (ISAB)
Chairman, Scientific Advisory Board, Beckman Foundation
Advisory Board, McGovem Institute for Brain Research

Commercial and Civic Activities

Founder and Principal Scientific Advisor, Schering-Plough's DNAX Research Institute

Director, Affymetrix

Consultant, Bay Area Bioscience Center

Consultant, Santa Clara County Biotechnology Education Partnership

Council of Advisors to San Francisco Unified School District

Advisory Board, ARISE (American Renaissance in Science Education)

192

BIBLIOGRAPHY
Paul Berg

1. Berg, P. and Joklik. W.K. Enzymatic phosphorylation of nucleose diphosphates. J.

Biol. Chem. 210: 657.

1955

2. Berg, P., Participation of adenyl-acetate-activating system. J. Am. Chem. Soc. 77:

3163.

1956

3. Berg, P. and Newton, G. Adenyl-acetates in the activation of acvl groups. Fed. Proc.

15:713.

4. Berg, P. Acyl adenylates: The synthesis and properties of adenyl acetate. J. Biol.

Chem. 222: 1015.

5. Berg, P. Acyl adenylates: The interaction of adenosine triphosphate and L-

methionme. J. Biol. Chem. 222: 1025.

6. Berg, P., Acyl adenylates: An enzymatic mechanism of acetate activation. J. Biol.

Chem. 222:991.

1957

7. Bers, P. Chemical synthesis and enzymatic utilization of adenyl amino acids. Fed

Proc. 16: 658.

8. Berg, P., Nismann, B., Bergmann, F.H. Observations on amino acid-dependent

exchanges of inorganic pyrophosphate and ATP. B.B.A. 26: 639.

1958

9. Ofengand, J., Bergmann, F., Berg, P. Enzymatic synthesis of an RNA-amino acid

complex. Fed. Proc. 17: 1123.

10. Berg, P., and Ofengand, E.J. An enzymatic mechanism for linking amino acids to

RNA. PNAS44:78.

1 1 . Berg, P. Studies on the enzymatic utilization of amino acyl adenylates: The

formation of adenosine triphosphate. J. Biol. Chem. 233: 601.

12. Berg, P. The chemical synthesis of amino acyl adenylates. J. Biol. Chem. 233: 608.

13. Berg, P. Role of magnesium in acetyl coenzyme A formation by acetothiokinase.

Science 129: 3353.

1959

193

14. Preiss, J., Berg. P., Ofengand, E.J., Bergmann, F.H., and Dieckmann, M. The

chemical nature of the RNA-amino acid compound formed by amino acid-
activating enzymes. PNAS 45: 319.

15. Bergmann, F.H., Berg, P., Preiss, J., Ofengand, E.J., and Dieckmann, M. Enzymatic

activation and transfer of amino acids to PJs'A. Fed. Proc. 18: 75 1 .

1960

16. Preiss, J., and Berg, P. Incorporation of ATP-C14 into polyribonucleotides. Fed.

Proc. 19: 317.

1961

17. Lagerkvist, U., Berg, P., Dieckmann, M. and Platt, F.W. Terminal nucleotide

sequences in ammo acid-acceptor RNA. Fed. Proc. 20, No. I.

18. Berg, Paul, Bergmann, Fred H., Ofengand, E.J. and Dieckmann, M. The enzymic

synthesis of amino acyl derivatives of ribonucleic acid. I. The mechanism of
leucyl-, valyl-, isoleucyl-, and methionyl ribonucleic acid formation. J. Biol.
Chefn. 236: 1726.

19. Bergmann, Fred H., Berg, Paul and Dieckmann, M. The enzymic synthesis of ammo

acyl derivatives of ribonucleic acid. II. The preparation of leucyl-, valyl-,
isoleucyl-, and methionyl ribonucleic acid synthetases for Escherichia coli. J.
Biol. Chem. 236: 1735.

20. Ofengand, E.J., Dieckmann, M. and Berg, P. The enzymic synthesis of amino acyl

derivatives of ribonucleic acid. III. Isolation of amino acid-acceptor ribonucleic
acids from Escherichia coli. J. Biol. Chem. 236: 1741.

21. Preiss, J., Dieckmann, M. and Berg, Paul. The enzymic synthesis of amino acyl

derivatives of ribonucleic acid. IV. The formation of the 3'-hydroxyl terminal
trinucleotide sequence of amino acid-acceptor ribonucleic acid. J. Biol. Chem.
236: 1748.

22. Berg, P. Specificity in protein synthesis. In Annual Review of Biochemistry

(J.M.Luck, F.W.Allen and G.'MacKinney, eds.). Vol.. 30, Annual Reviews, Inc.,
Palo Alto, CA, pp. 293-324.

23. Chamberlin, Michael and Berg, Paul. Deoxyribonucleic acid-directed synthesis of

ribonucleic acid by an enzyme from Escherichia coli.. PNAS 48: 81.

24. Wood, William B. and Berg, Paul. The effect of enzymatically synthesized

ribonucleic acid on amino acid incorporation by a soluble protein-ribosome system
from Escherichia coli.. PNAS 48: 94.

25. Berg, Paul. Assay and preparation of yeast aceto-CoA-kinase. In Methods in

Enzymology (S.P. Colowick and N.O. Kaplan, eds.). Vol. V, Academic Press Inc.,
New York, pp. 461-466.

194

26. Wood, W.B. The effect of enzymatically synthesized RNA on ammo acid

incorporation by a soluble protein-ribosome system from E. coli. Fed. Proc. 21,
No. 2.

27. Chamberlin, M. and Berg, P. Enzymatic synthesis of specific polyribonudeotides.

Fed. Proc. 21, No. 2.

28. Berg, P., and Lagerkvist, U. An attempt to correlate amino acid specificity with

terminal nucleotide sequence in amino acyl RNA formation. In Acides
Ribonucleiques et Polyphosphates, Structure, Synthese et Fonctions. Colloq.
Intern. Centre Nat. Rech. Sci. No. 106, Strasbourg, Editions du Centre National de
la Recherche Scientifique, Paris, pp. 259-276.

29. Berg, Paul, Lagerkvist, U. and Dieckmann, M. The enzymic synthesis of amino acyl

derivatives of ribonucleic acid. V. Nucleotide sequences adjacent to the . .
pCpCpA end groups. J. Mol. Biol. 5: 139.

30. Berg, P., Lagerkvist, Ulf and Dieckmann, M. The enzymic synthesis of amino acyl

derivatives of ribonucleic acid. VI. Nucleotide sequences adjacent to the . .
pCpCpA end groups of isoleucine- and leucine-specific chains. J. Mol. Biol. 5:
159.

3 1 . Berg, Paul. Studies on the contribution of nucleic acids to the specificity of protein

synthesis. In Basic Problems in Neoplastic Disease (A. Gallhom and E.
Hirschberg, eds.). Columbia University Press, New York, pp. 15-34.

1963

32. Berg, P., Fancher, H. and Chamberlin, M. The synthesis of mixed polynucleotides

containing ribo- and deoxyribo-nucleotides by purified preparations of DNA
polymerase from Escherichia coli. In Informational Macromolecules (H.J. Vogel.
V. Bryson and J.O. Lampen, eds.). Academic Press Inc., New York, pp. 467-483.

33. Littauer, U.Z., Muench, K., Berg, P., Gilbert, W. and Spahr, P.P. Studies on

methylated bases in transfer RNA. Cold Sprins Harbor Symposia on Quantitative
Biology XXVIII: 157-159..

34. Chamberlin, Michael. Baldwin, Robert L. and Berg, Paul. An enzymically

synthesized RNA of alternating base sequence: physical and chemical
characterization. J. Mol. Biol. 7: 334.

35. Chamberlin, M. and Berg, P. Studies on DNA-directed RNA polymerase: formation

of DNA-RNA complexes with single-stranded 6X 174 DNA as template. Cold
Spring Harbor Symp. Quant. Biol. 28: 67.

36. Wood, W.B. and Berg, P. Studies on the "messenger" activity of RNA synthesized

with RNA polymerase. Cold Spring Harbor Symp. Quant. Biol. 28: 237.

1964

37. Chamberlin, M., and Berg, P. Mechanism of RNA polymerase action: Formation of

DNA-RNA hybrids with single-stranded templates. J. Mol. Biol. 8: 297.

38. Muench, K.H., and Berg, P. Purification of transfer RNA. Fed. Proc. 23, No. 2.

195

39. Norris, AT., and Berg, P. Purification and properties of isoleucyl S-RNA synthetase

from Escherichia coli.. Fed. Proc. 23, No. 2.

40. Chamberlin, M, and Berg, P. Mechanism of RNA polymerase action:

characterization of the DNA-dependent synthesis of polyadenylic acid. J. Mol.
Biol. 8: 708.

41. Wood, W.B., and Berg, P. Influence of DNA secondary structure on DNA-

dependent polypeptide synthesis. J. Mol. Biol. 9: 452.

42. Norris, A.T. Mechanism of aminoacytl RNA synthesis: Studies with isolated

aminoacyl adenylate complexes of isoleucyl RNA synthetase. PNAS 52: 330.

43. Berg, P., and Chamberlin, M. On the transcription of DNA sequences by RNA

polymerase. Bull. Soc. Chim. Biol. 46: 1427.

1965

44. Berg, P., Kornberg, R.D., Fancher, H., and Dieckmann, M. Competition between

RNA polymerase and DNA polymerase for the DNA template. Biochem. Biophys.
Res. Comm. 18: 932.

45. Calendar, R., and Berg, P. Tryosyl RNA synthetases from E. coli and B. subrilis.

Fed. Proc. 24: 490.

46. Muench, K.H. Resolutions of tRNA on hydroxylapatite columns. Fed. Proc. 24:

1959.

47. Jackson, J.F., Kornberg, R.D., Berg, P., RajBhandary, U.L., Stuart, A., Khorana,

H.G. and Kornberg, A. On the heterogeneity of the deoxyribonucleic acid
associated with crystalline yeast cytochrome b2- Biochim. Biophys. Acta 108: 243.

1966

48. Calendar, R. and Berg, P. Tyrosyl tRNA synthetase from E. coli,. In Procedures in

Nucleic Acid Research (Cantoni and Davies, eds.). Harper and Row, Inc., New
York, p. 384.

49. Baldwin, A.N. and Berg, P. Purification and properties of isoleucyl RNA synthetase

from E. coli . In Procedures in Nucleic Acid Research (Cantoni and Davies, eds.).
Harper and Row, Inc., New York, p. 400.

50. Baldwin, A.N., and Berg, P. Purification and properties of isoleucyl ribonucleic acid

synthetase from E. coli. J. Biol. Chem. 241: 831.

51. Baldwin, A.N., and Berg, P. Transfer ribonucleic acid-induced hydrolysis of

valyladenylate bound to isoleucyl ribonucleic acid synthetase. J. Biol. Chem. 241:
839.

52. Muench, K.H., Berg, P. Fractionation of transfer ribonucleic acid by gradient

partition chromatography on sephadex columns. Biochem. 5: 970.

196

53. Muench, K. H. and Berg, P. Resolution of aminoacyl transfer RNA by
hydroxylapatite chromatography. Biochem. 5: 982.

54. Calendar, R. and Berg, P. Purification and physical characterization of tyrosyl

ribonucleic acid synthetases from E. coli and Bacillus sublilis. Biochem. 5: 1681 .

55. Calendar, R. and Berg, P. The catalytic properties of tyrosyl ribonucleic acid

synthetases from E. coli and Bacillus subrilis. Biochem. 5: 1690.

56. Carbon, J.., Berg, P. and Yanofsky, C. Studies of missense suppression of the

tryptophan synthetase A-protem mutant A36. PNAS 56: 764.

57. Carbon, J., Berg, P. and Yanofsky, C. Missense suppression due to a genetically

altered tRNA. Cold Spring Harbor Symp. 31: 487.

58. Jones. O.W. and Berg, P. Studies on the binding of RNA polymerase to

polynucleotides. J. Mol. Biol. 22: 199.

1967

59. Calendar, R. and Berg, P. D-tyrosyl RNA: Formation, hydrolysis and utilization for

protein synthesis. J. Mol. Biol. 26: 39.

60. Yarus, M. and Bers. P. Recognition of tRNA by aminoacyl tRNA synthetases. J.

Mol. Biol. 28: 479.

61. Slapikoff, S. and Berg, P. Mechanism of ribonucleic acid polymerase action. Effect

of nearest neighbors on competition between uridine triphosphate and uridine
tnphosphate analogs for incorporation into ribonucleic acid. Biochem. 6: 3654.

62. Jones, O.W., Dieckmann, M., and Berg, P. Ribosome-induced dissociation of RNA

from an RNA polymerase DNA-RNA complex. J. Mol. Biol. 31: 177.

63. Reid. P., and Berg, P. T4 bacteriophage mutants suppressible by a missense

suppressor which inserts glycine in place of arginine for the codon AGA. J. Virol.
2: 905.

1969

64. Hill, C.W., Foulds, J., Soil, L., and Berg, P. Instability of a missense suppressor

resulting from a duplication of genetic material. J. Mol. Biol. 39: 563.

65. laccarino, M., and Berg, P. The requirement of sulfhydryl groups for the catalytic

and tRNA recognition functions of isoleucyl-tRNA-synthetase. J. Mol. Biol. 42:
151.

66. Yarus, M. and Berg, P. Recognition of tRNA by isoleucyl-tRNA synthetase. II.

Effect of substrates on the dynamics of tRNA-enzyme interaction. J. Mol. Biol.
42: 171.

67. Hill, C.W., Schiffer, D., and Berg, P. Transduction of merodiploidy: Induced

duplication of recipient genes. J. Bact. 99: 274.

197

68. Soil, L., and Berg, P. Recessive lethais: A new class of nonsense suppressors in

Escherichia coli . PNAS 63: 392.

69. Soil, L., and Berg, P. Recessive lethal nonsense suppressor in Escherichia coli

which inserts glutamine. Nature 233: 1340.

70. Yarus, M, and Berg, P. On the properties and utility of a membrane filter assay in

the study of isoleucyl-tRNA synthetase. Analytical Biochem 35: 450.

71. Primakoff, P., and Berg, P. Stringent control of transcription of phage080psu3. Cold

Spring Harbor Symposia on Quantitative Biology 35: 391.

72. Folk, W.R., and Berg, P. Isolation and partial characterization of Escherichia coli

mutants with altered glycyl transfer ribonucleic acid synthetases. J. Bact. 102: 193.

73. Folk, W.R., and Berg, P. Characterization of altered forms of glycyl transfer

ribonucleic acid synthetase and the effects of such alterations on aminoacyl transfer
ribonucleic acid synthesis in vivo. J. Bact. 102: 204.

74. Arndt, D., and Berg, P. Isoleucyl transfer ribonucleic acid synthetase is a single

polypeptide chain. J. Biol. Chem. 245: 665.

75. Cuzin, F., Vogt, M., Dieckmann, M., and Berg, P. Induction of virus multiplication

in 3T3 cells transformed by a thermosensitive mutant of polyoma virus. II.
Formation of oligomeric polyoma DNA molecules. J. Mol. Biol. 47: 317.

76. Ostrem, D.L.. and Berg, P. Glycyl-tRNA synthetase: An oligomeric protein

containing dissimilar subunits. PNAS 67: 1967.

1971

77. Berg, P. The viral genome in transformed cells. Proc. Roy. Soc. Lond. B. 177: 65.

78. Arndt-Jovin, D.J., and Berg, P. Quantitative binding of 125]-concanavaJin A to

normal and transformed cells. J. Virol. 8: 716.

79. laccanno, M., and Berg, P. Isoleucine auxotrophy as a consequence of a

mutationally altered isoleucyl-transfer ribonucleic acid synthetase. J. Bact. 105:

527.

80. Folk, W. Molecular Weight of Escherichia coli glutaminyl transfer ribonucleic acid

synthetase, and isolation of its complex with glutamine transfer ribonucleic acid.
Biochem 10: 1728.

8 1 . Folk, W.R., and Berg, P. Duplication of the structural gene for glycyl-transfer RN A

synthetase in Escherichia coli. J. Mol. Biol. 58: 595.

82. Folk, W.R., and Yaniv, M. Coding properties and nucleotide sequence. Sequences
of E. coli glutamine tRNAs. Nature New Biology 237: 165.

198

83. Jackson, D.A., Symons, R.H., and Berg, P. Biochemical method for inserting new

genetic information into DNA of Simian Virus 40: Circular SV40 DNA molecules
containing lambda phage genes and the galactose operon of Escherichia coli.
PNAS 69: 2904.

84. Morrow, J., and Berg, P. Cleavage of Simian Virus 40 DNA at a unique site by a

bacterial restriction enzyme. PNAS 69: 3365.

1973

85. Beard, P., Morrow, J.F., and Berg, P. Cleavage of circular superhelical Simian Virus

40 DNA to a linear duplex by S\ nuclease. J. Virol. 12: 1303.

86. Berg, P. Suppression: A subversion of genetic decoding. Harvey Lectures 67: 247.

87. Morrow, J.F., and Berg, P. Location of the T4 gene 32 protein binding site on

Simian Virus 40 DNA. J. Virol. 12: 1631.

88. Morrow, J.F., Berg, P., Kelly, J.K., and Lewis, A.M. Mapping of Simian Virus 40

early functions on the viral chromosome. J. Virol. 12: 653.

1974

89. Beard, P., and Berg, P. A convenient micro method for the quantitation of closed

circular deoxyribonucleic acid. Biochem. 13: 2410.

90. Berg, P., Baltimore, D., Boyer, H., Cohen, S., Davis, R., Hogness, D., Nathans, D.,

Roblm, R., Watson, J., Weissman, S., and Zinder, N. Potential biohazards of
recombinant DNA molecules. Science 185: 303.

91. Mertz, J., Carbon, J., Herzberg, M., Davis, R., and Berg, P. Isolation and

characterization of individual clones of Simian Virus 40 mutants containing
deletions, duplications and insertions in their DNA. Cold Spring Harbor Symp.
Quant. Biol. 39: 69 and in Viral Transformation and Endogenous Viruses (Kaplan,
A.S., Ed.). Academic Press, New York, 1974.

92. Mertz, J., a~nd Berg, P. Defective Simian Virus 40 genomes: Isolation and growth of

individual clones. Virology 62: 1 12.

93. Mertz, J., and Berg, P. Viable deletion of Simian Virus 40: Selective isolation by

means of a restriction endonuclease from Hemophilus parainfluenzae. PNAS 71:
4879.

94. Ostrem, D., and Berg, P. Glycyl transfer ribonucleic acid synthetase from E. coli:

Purification, properties, and substrate binding. Biochemistry 13: 1338.

95. Shenk, T., Rhodes, C, Rigby, P., and Berg, P. Mapping of mutational alterations in

DNA in S] nuclease: The location of deletions, insertions and temperature-
sensitive mutations in SV40. Cold Spring Harbor Symp. Quant. Biol. 39: 61.

96. Yaniv, M., Folk, W., Berg, P., and Soil, L. A single mutational modification of a

tryptophan-specific transfer RNA permits aminoacylation by glutamine and
translation of the codon UAG. J. Mol. Biol. 86: 245.

199

1975

97. Berg, P., Baltimore, D., Brenner, S., Roblin, R.O. and Singer, M. Asilomar

conference on recombinant DNA molecules. Science 188: 991.

98. Berg, P., Baltimore, D., Brenner, S., Roblin, R.O. and Singer, M. Summary

statement of the Asilomar Conference on Recombinant DNA Molecules. PNAS
72: 1981-1984.

99. Carbon, J., Shenk, T.E., and Berg, P. Construction in vitro of mutants of simian

virus 40: Insertion of a poly(dA.dT) segment at the Hemophilus parainfluenza II
restriction endonuclease cleavage sites. J. Mol. Biol.98: 1.

100. Griffith, J., Dieckmann, M., and Berg, P. Electron microscop;e localization of a

protein bound near the origin of Simian Virus 40 DNA replication. J. Virol. 15:
167-172.

101 . Carbon, J., Shenk, T.E., and Berg, P. Biochemical prodcedure for production of

small deletions in simian virus 40 DNA. PNAS 72: 1392.

102. DePamphilis, M.L., Beard, P., and Berg, P. Synthesis of superhelical simian virus

40 deoxyribonucleic acid in cell lysates. J. Biol. Chem. 250: 4340.

103. DePamphilis, M.L., and Berg, P. Requirement of a cytoplasmic fraction for

synthesis of SV40 deoxyribonucleic acid in isolation nuclei. J. Biol. Chem. 250:

4348.

104. Shenk, T.E., Rhodes, C, Rigby, P.W.J., and Berg, P. Biochemical method for

mapping mutational alterations in DNA with SI nuclease: The location of
deletions and temperature-sensitive mutations in simian virus 40. PNAS 72: 989.

1976

105. Berg. P. From enzyme chemistry to genetic manipulation. In Reflections on

Biochemistry. Pergamon Press, New York, p. 253.

106. Berc. P., Singer, M. Seeking wisdom in recombinant DNA research. Fed. Proc. 35:

2542.

107. Cole, C., Landers, T., Goff, S., Manteuil-Brutlag, S., Berg, P. Deletion mutants of

SV40. Abstract from SV40, Polyoma and Adenoviruses, proceedings of the
Tumor Virus Meeting August 18-20, Cold Spring Harbor, New York, p. 1.

108. Goff, S., Berg, P. Construction, propagation and expression of a hybrid virus

containing SV40 and lambda DNA segments. Abstract from SV40, Polyoma and
Adenoviruses, proceedings of the Tumor Virus Meeting August 18-20, Cold
Spring Harbor, New York, p. 9.

109. Goff, S., Berg, P. Construction of hybrid viruses containing SV40 and X phage

DNA segments and their propagation in cultured monkey cells. Cell 9: 695.

200

] 10. Shenk, T.E., Berg, P. Isaolation and propagation of a segment of the simian virus 40
genome containing the origin of DNA replication. PNAS 73: 1513.

111. Shenk, T.E., Carbon, J., Berg, P. Construction and analysis of viable deletion

mutants of simian virus 40. J. Virol. 18: 664.

1 12. Shishido, K., Berg, P. Restriction endonuclease from Haemophilus gallinarum

(Hgal) cleaves polyoma DNA at four locations. J. Virol. 18: 793.

1 13. Wilson, J.H., DePamphilis, M., Berg, P. Simian Virus 40-permissive cell

interactions: Selection and characterization of spontaneously arising monkey cells
that are resistant to Simian Virus 40 infection. J. Virol. 20: 391.

1977

1 14. Berg, P. Biochemical pastimes . . . and future times. The Eighth Feodor Lynen

Lecture. In Molecular Cloning of Recombinant DNA. Academic Press, p. 1.

115. Berg, P. Mapping the mammalian genome. Forum on Recombinant DNA

Research, National Academy of Sciences, p. 62.

1 16. Berg, P. Recombinant DNA research can be safe. TIBS 2: 1.

1 17. Berg, P. Genetic engineering: Challenge and responsibility. AMBIO 6: 253.

118. Christiansen, G., Landers, T., Griffith, J., Berg, P. Characterization of components

released by alkali disruption of Simian Virus 40. J. Virol. 21: 1079.

1 19. Cole, C, Landers, T., Goff, S. P., Brutlag, S.M., Berg, P. Physical and genetic

characterization of deletion mutants of Simian Virus 40 constructed in vitro. J.
Virol. 24: 277.

120. DNA segments and their propagation in cultured monkey cells. In Recombinant

Molecules: Impact on Science and Society (Beers, R.F. and Bassett, E.G., eds.).
Raven Press, p. 285.

121. Goff, S.P., Berg, P. Structure and formation of circular dimers of Simian Virus 40

DNA. J: Virol. 24: 295.

122. Rigby, P.W.J., Dieckmann, M., Rhodes, C., Berg, P. Labeling deoxyribonucleic

acid to high specific activity in vitro by nick translation with DNA polymerase I.
J.Mol.Biol. 113:237.

123. Villarreal, L., Berg, P. Hybridization in situ of SV40 plaques: Detection of

recombinant SV40 virus carrying specific sequences of nonviral DNA. Science
196: 183.

1978

124. Bouck, N., Beales, N., Shenk, T., Berg, P., Di Mayorca, G. New region of the

Simian Virus 40 genome required for efficient viral transformation. PNAS 75:
2473.

201

125. Crawford, L.V., Cole, C.N., Smith, A.E., Paucha, E., Tegtmeyer, P., Rundell, K.,

Berg, P. Organization and expression of early genes of Simian Virus 40. PNAS
75: 117.

126. Goff, S.P., Berg, P. Excision of DNA segments introduced into cloning vectors by

the poly(dA dT) joining method. PNAS 75: 1763.

127. Goff, S.P., Rambach, A. Sstl: A restriction endonuclease from Streptomyces sp.

Stanford. Gene 13: 347.

128. Hsu, M.-T., Berg, P. Altering the specificity of restriction endonuclease: Effect of

replacing Mg2+ with Mn2+. Biochemistry 17: 131.

129. Rigby, P.W.J., Berg, P. Does Simian Virus 40 DNA integrate into cellular DNA

during productive infection? J. Virol. 28: 475.

130. Villarreal, L., White, R. and Berg, Paul. Mutational alterations within the SV40

leader segment generate altered 16S and 19S. J. Virol. 29, 209-219.

131. Mulligan, R.C., Howard, B.H. and Berg, Paul. Synthesis of rabbit (3-globin

recombinant genome. Nature 277, 108-1 14.

132. Contreras, R., Cole, C, Berg, Paul and Fiers, W. Nucleotide sequence analysis of

two simian virus 40 mutants with deletions in the late region of the genome. J.
Virol. 29, 789-793.

133. Volckaert, G., Feunteun, J., Crawford, L.V., Berg, Paul and Fiers, W. Nucleotide

sequence deletions within the coding region for small-t antigen of simian virus 40.
J. Virol. 30, 674-682.

134. Cole, C., Crawford, L.V. and Berg, Paul. Simian virus 40 mutants with deletions at

the 3' end of the early region are defective in adenovirus helper function. J. Virol.
30,683-691.

135. Van Heuverswyn, H., Cole, C., Berg, Paul and Fiers, W. Nucleotide sequence

analysis of two simian virus 40 mutants with deletions-in the region coding for the
carboxyl terminus of the T antigen. J. Virol. 30, 936-941.

136. Goff, S.P and Berg, Paul. Construction, propagation and expression of simian virus

40 recombinant genomes containing the Escherichia coli gene for thymidine kinase
and a Saccharomyces cerevisae gene for tyrosine transfer RNA. J. Mol. Biol. 133,
359.

137. Magnusson, G. and Berg, Paul. Construction and analysis of viable deletion mutants

of polyoma virus. J. Virol. 32, 523-529.

138. Mulligan, R.C., Howard, B.H. and Berg, Paul. Synthesis of rabbit P globin in

cultured monkey kidney cells infected with SV40 P globin recombinant genomes.
ICN UCLA Symposia on Eucaryotic Gene Regulation, Academic Press Inc.

202

139. Berg, Paul. The physical and genetic organization of a viral genome. Crit. Rev.

Biochem. 7, 75-82.

1980

140. Mark, D.F. and Berg, Paul. A third splice site in SV40 early mRNA. Cold Spring

Harbor Symp. Quant. Biol. Vol. XLIV, 55-62.

141. Mulligan, R.C., White R.T. and Berg, Paul. Formation of p-globin following

infection with recombinants containing rabbit (3-globin cDNA at different locations
of SV40s late region. Miami Winter Symposium, 201-216.

142. Buchmann, A.R., Burnett, L. and Berg, Paul. The nucleotide sequence. In Tumor

Viruses, 2nd Ed. (J. Tooze, Ed.) Cold Spring Harbor Monogr. Ser. Wb, 799-829.

143. Mulligan, R.C. and Berg, Paul. Expression of a bacterial gene in mammalian cells.

Science 209, 1422-1427.

144. Fraley, R., Subramani, S., Berg, Paul and Papahadjopoulos, D. Introduction of

liposome-encapsuled SV40 DNA into cells. J. Biol. Chem. 255, 10431-10435.

145. Mulligan, R.C. and Berg, Paul. Selection for animal cells that express the

Escherichia coli gene coding for xanthine-guanine phosphoribosyl transferase.
Proc. Natl. Acad. Sci. USA 78, 2072-2076.

146. Mulligan. R.C. and Berg, Paul. Factors governing the expression of a bacterial gene

in mammalian cells. Mol. Cell. Biol. 1, 449-459.

147. Berg, Paul. Dissections and reconstructions of genes and chromosomes. Bioscience

Reports 1, 269-287.

148. Berg. Paul. Dissections and reconstructions of genes and chromosomes. Science

213, 246.

149. Berg, Paul. Zerlegung und Rekonstruktion von Genen und Chromosomen.

Angewandte Chemie 93, 10, 885-893.

150. Subrarruni, S., Mulligan, R.C. and Berg, Paul. Expression of the mouse

dihydrofolate reductase cDNA in simian virus 40 vectors. Mol. Cell. Biol. 9, 854-
864.

151. Lee, F., Mulligan, R.C., Berg, Paul and Ringold, G. Glucorticoids regulate

expression of dihydrofolate reductase cDNA in mouse mammary tumor virus
chimeric plasmids. Nature 294, 228-232.

152. Southern, P.J., Howard, B.H. and Berg, Paul. Construction and characterization of

SV40 recombinants with (3-globin cDNA substitutions in their early regions. J.
Mol. Appl. Gen. 1, 177-190.

1982

203

153. Okayama, Hiroto and Berg, Paul. High efficiency cloning of full length cDNA.

Molec. and Cell. Biol. 2, 161-170.

154. White, R.T., Villarreal, L.P. and Berg, Paul. Simian virus 40 rabbit (3-globin

recombinants lacking late mRNA splice sites express cytoplasmic RNAs with
altered structures. J. Virol. 42, 262-274.

155. Southern, P.J. and Berg, Paul. Transformation of mammalian cells to antibiotic

resistance with a bacterial gene under control of the SV40 early region promoter.
J. Mol. & Applied Gen. 1, 327-341.

156. Fromm, M. and Berg, Paul. Deletion mapping of DNA regions required for SV40

early region promoter function in vivo. J. Mol. & Appl. Gen., 1, 457-48 1 .

157. Canaani, D. and Berg, Paul. Regulated expression of human interferon b] gene after

transduction into cultured mouse and rabbit cells. Proc. Natl. Acad. Sci. USA 79,
5166-5170.

158. Goodman, H.M., Berg, P., Clark, S., Cordell, B., Diamond, D., Nyugen-Huu, C,

Kan, Y.W., Lebo, R.V. Structure, evolution and expression of mammalian insulin
genes. Mol. Gen. Neuroscience.

1983

159. Okayama, Hiroto and Berg, Paul. A cDNA cloning vector that permits expression

of cDNA inserts in mammalian cells. Mol. & Cell. Biol. 3, 2, 280-289.

160. Nicolas, Jean-Francois and Berg, Paul. Regulation of expression of genes

transduced into embryonal carcinoma cells. Teratocarcinoma Stem Cells, Cold
Spring Harbor.

161 . Oi, V.T., Morrison, S.L. , Herzenberg, L.A. and Berg, P. Immunoglobulin gene

expression in transformed lymphoid cells. PNAS, USA, 80, 825-829.

162. Fromm, M. and Berg, P. Transcription in vivo from SV40 early promoter deletion

mutants without repression by large T antigen. J. Mol. Appl. Gen., 2, 127-135.

163. Fromm, M. and Berg, Paul. SV40 early and late region promoter function are

enhanced by the 72 base pair repeat inserted at distant locations and inverted
orientations. Mol. and Cell. Biol. 3, 991-999.

164. Jolly, D.J., Okayama, H., Berg, P., Esty, A.C., Filpula, D., Bohlen, P., Johnson,

G.G., Shively, J.E., Hunkapillar, T., and Friedmann, T. Isolation and
characterization of a full-length expressible cDNA for human hypoxanthine
phosphoribosyl transferase. PNAS, USA, 80, 477-481.

165. Subramani, S. and Berg, P. Homologous and non homologous recombination in

monkey cells. Mol. & Cell. Biol. 3, 1040-1052.

1984

166. Buchman, A.R., Fromm, M. and Berg, P. Complex regulation of Simian Virus 40

early-region transcription from different overlapping promoters. Molec. and Cell
Biol. 4, 1900-1914.

204

167. Buchman, A.R. and Berg, P. Unusual regulation of Simian Virus 40 early-region

transcription in genomes containing two origins of DNA replication. Molec. and
Cell. Biology 4, 1915-1928.

168. Smith, A.J.H. and Berg, Paul. Homologous recombination between defective neo

genes in mouse 3T6 cells. Cold Spring Harbor Laboratory, Vol. XLIX.

169. Chin, D.J., Gil, G., Russell, D.W., Liscum,, L., Luskey, K.L., Basu, S.K., Okayama,

H., Berg, P., Goldstein, J.L. and Brown, M.S. Nucleotide sequence of 3-hydroxy-
3-methyl-glutaryl coenzyme A reductase, a glycoprotein of endoplasmic reticulum.
Nature 308, No. 5960, 613-617.

1985

170. Naumovski, L., Chu, Gilbert, Berg, Paul and Friedberg, E.G. RAD3 gene of

Saccharomyces cerevisiae: nucleotide sequence of wild-type mutant alleles,
transcript mapping, and aspects of gene regulation. Molec. and Cell. Biol. 5: 17-
26.

171. Okayama, H. and Berg, P. Bacteriophage lambda vector for transducing a cDNA

clone library into mammalian cells. Molec. & Cell. Biol. 5, 1 136-1 142.

172. Chu, G. and Berg, P. Rapid assay for detection of Escherichia coli xanthine-guanine

phosphoribosyltransferase activity in transduced cells. Nucleic Acids Research 13A
2921-2930.

173 Barsoum, J. and Berg, P. SV40 minichromosomes contain torsionally strained DNA
molecules. Molec. and Cell. Biol. 5, 3048-3057.

174. Dennis, E. and Berg, P. Transcription from a plant gene promoter animal cells.
Nucleic Acids Research 13, No. 22, 7945- 7957.

175. Canaani, D., Naiman, T., Teitz, T. and Berg, P. Immortalization of xeroderma

pigmentosum cells by simian virus 40 DNA having a defective origin of DNA
replication. Somatic Cell and Molec. Genetics 12, No.. 1, 13-20.

176. Kadesch, T. and Berg, P. Effects of the position of the simian virus 40 enhancer on

the expression of multiple transcription units in a single plasmid. Molec. and Cell.
Biol. 6, 2593-2601.

177. Thelander, L. and Berg, P. Isolation and characterization of full-length cDNA

clones encoding the Ml and M2 subunits of mouse ribonucleotide reductase.
Molec. and Cell. Biol. 6, 3433-3442.

178. Peabody, D. and Berg, P. Termination-reinitiation occurs in the translation of

mammalian cell mRNAs. Molec. and Cell. Biol. 6, 2695-2703.

179. Peabody, D., Subramani, S. and Berg, P. The effect of upstream reading frames on

translation efficiency in SV40 recombinants. Molec. and Cell. Biol. 6, 2704-271 1.

205

Bacillus Molecular Genetics and Biotechnology Applications. Ed. by A.T.
Ganesan and James A. Hoch, p. 3, Academic Press, Inc., New York.

180. McPhaul, M. and Berg, P. Formation of functional asialoglycoprotein receptor after

transfection with cDNAs encoding the receptor proteins. Proc. Natl. Acad. Sci.,
USA 83, 8863-8867.

1987

181. McPhaul, M. and Berg, P. Identification and characterization of cDNA clones

encoding two homologous proteins that are part of the asialoglycoprotein receptor.
Molec. and Cell. Biol. 7, 1841-1847.

182. Chu, G., Hayakawa, H. and Berg, P. Electroporation for the efficient transfection

of mammalian cells with DNA. Nucleic Acids Research, Vol. 15, No. 3.

183. Chu, G. and Berg, P. DNA cross-linked by cisplatin: A new probe for the DNA

repair defect in Xeroderma Pigmentosum. Molec. Biol. Med. 4, 277-290.

1988

184. Reichardt, J. and Berg, P. Cloning and characterization of a cDNA encoding

human galactose-1 -phosphate uridyl transferase. Molec. Biol. Med. 5, 107-122.

185. Margolskee, R., Kavathas, P. and Berg, P. Epstein-Barr virus shuttle vector for

stable episomal replication of cDNA expression libraries in human cells. Molec
and Cell. Biol. 8, 2837-2847.

186. Buchman, A. and Berg, P. A comparison of intron-dependent and intron-

independent gene expression. Molec. and Cell. Biol. 8, 4395-4405.

187. Jasin, M. and Berg, P. Homologous integrations in mammalian cells without target

selection. Genes & Development 2, 1353-1363.

1 88. Reichardt, J. and Berg, P. Conservation of short patches of amino acid sequence

amongst proteins with a common function but evolutionarily distinct origins:
implications for cloning genes and for structure-function analysis. Nucleic Acids
Research 16, 9017-9026.

1990

189. Jasin, M., Elledge, S.J., Davis, R.W., and Berg, P. Gene targeting at the human CD4

locus by epitope addition. Genes & Development 4: 157-166.

190. Stuhlmann, H., Dieckmann, M. and Berg, P. Transduction of cellular neo mRNA by

retroviral-mediated recombination. J. Virol. 64: 5783-5796.

191. Pontius, B. and Berg, P. Renaturation of complementary DNA strands mediated by

purified mammalian heterogeneous nuclear ribonucleoprotein Al protein:
Implications for a mechanism for rapid molecular assembly. PNAS 87: 8403-
8407.

192. Singer, M. and Berg, P. Genes and Genomes: A Changing Perspective. University

Science Books, Mill Valley, CA.

206

1991

193. Jessberger, R. and Berg, P. Repair of deletions and double strand gaps by

homologous recombination in a mammalian in vitro system. Molec. and Cell.
Biol. 11: 445-457.

194. Berg, P. All our collective ingenuity will be needed. FASEB J 5: 75.

195. Luria, S., Chambers, I., and Berg, P. Expression of the type 1 immunodeficiency

virus Nef protein in T-cells prevents antigen receptor mediated induction of TL-2
mRNA. PNAS 88:5326-5330.

196. Berg, P. Reverse genetics: its origins and prospects. Biotechnology 9: 342-344.

197. Pontius, B. and Berg, P. Rapid renaturation of complementary DNA strands

mediated by cationic detergents: A role for high-probability binding domains in
enhancing the kinetics of molecular processes. PNAS 88: 8237-8241.

1992

198 Stuhlmarm, H., and Berg, P. Homologous recombination of copackaged retrovirus
RNAs during reverse transcription. J. Virol. April: 2378-2388.

199. Pontius, B.W. and Berg, P. Rapid assembly and disassembly of complementary

DNA strands through an equilibrium intermediate state mediated by Al nhRNP
protein. J. Biol. Chem 267: 13815-13818.

200. Berg, P. and Singer, M. Dealing with Genes: The Language of Heredity.

University Science Books, Mill Valley, CA..

1993

201. Jessberger, R., Podust V., Hiibscher, U. and Berg, P. A mammalian protein complex

that repairs double-strand breaks and deletions by recombination. J. Biol. Chem.
268: 15070-15079.

202. Berg, P. Co-chairman's remarks: reverse genetics: directed modification of DNA

for functional analysis. Gene 135: 1 62-164.

1995

203. Firmenich, A., Elias-Arnanz, M., and Berg, P. A novel allele of Saccharomyces

cerevisiae RFA1 that is deficient in recombination and repair and suppressible by
RAD52. Molec. and Cell. Biol. 15(3): 1620-1631.

204. Zieler, H., Walberg, M., and Berg, P. Suppression of mutations in two 5. cerevisiae

genes by the adenovirus El A protein. Molec. and Cell. Biol. 15: 3227-3237.

205. Hays, S.L., Firmenich, A.A., and Berg, P. Complex formation in yeast double-

strand break repair: Participation of RadSl, Rad52, Rad55, and Rad57 proteins.
PNAS 92: 6925-6929.

209

Paul Berg

Application #10170 \_l %»^ j

We are trying to learn how viral genes can alter the growth
properties of a cell and make it cancerous. An important goal of our
research is to learn how genetic information carried by a virus
chromosome can be integrated into the genetic machinery of a
mammalian cell and thereby influence the properties of that cell.
To study this we are examining a mutant virus which is unable to
transform cells into tumor cells under certain conditions. We hope
to define the defective function and to determine its role in the inte
gration process. In practical terms, if we could understand how new
genetic information can be inserted and maintained in a foreign
chromosome, we might not only be closer to the secret of cancer,
but also on the road to learning how to modify the genetic constitution
of cells by integration of other types of DNA molecules.

., _.

sip uiojg uotssnmad saimbai uoponpoodai jsqimj 'Xpio asn aouawjai jqj si

210

of Preliminary Planning of Basic Sciences Sub- Committee
of Cancer Center Planning Group

A strong Basic Sciences Program is an essential element
any effective Cancer R.crearch effort. Without the continual infusion
basic science techniques, knowledge, and ideas, the momentum and
^inspiration for the needed research developments on the Cancer Problem
••would soon founder and dry up. With this premise, and indeed strongly
rbeld conviction, the Basic Sciences Sub-Committee of the Cancer Center
i. Planning Group has conducted its preliminary planning by considering
following three general questions:

|l) Stanford's present strengths in those areas of Basic Sciences Research
»* which are relevant or bear directly on the Cancer Problem.

-2) Stanford's needs for expanding , and strengthening existing programs

••"as well as development of new programs in various areas of Cancer-

? related Basic Sciences Research.

i .

\:3) Ways in which the Cancer Center's Basic Sciences Research Activities

should be organized so as to enhance the Center's Clinical efforts as well
' as be consistent with Medical School's existing Research and Teaching

Programs. . ..

No definitive conclusions have been reached yet on any of
; these three problems but the following outline attempts to summarize some of

our thinking in these areas. For clarity and brevity, the first two
"questions have been considered together under each heading.

1 ) Present Strengths and Activities in Basic Sciences Research
Relevant to the Cancer Problem.

A) Molecular and Regulatory Biology of Animal and Human Cells:

Stanford's emphasis in this area of research has dealt mainly
with bacterial cells and their viruses but more recently there has
been an expansion of research with eukaryote systems. In spite
of Stanford's acknowledged and recognized leadership in this field
an objective review of these activities shows that it is the
intensiveness rather than extensiveness that is our strength.

i) Basic Mechanisms and Structures Concerned with Replication,
Transcription, and Translation.

Perhaps strongest is research centered about the
enzymatic synthesis of nucleic acids, and in particular in
prokaryote systems. Dr. Arthur Kornberg (Biochemistry)
is continuing his elegant studies on enzymes involved in DNA
synthesis. Dr. 1. R. Lehman (Biochemistry) has been concerned
for many years with various enzymes concerned with DNA

~ K>

211

metabolism, and is currently studying the enzymatic mechanisms
of genetic recombination in E. coli . Dr. A. D. Kaiser
(Biochemistry) has worked at a slightly different level of DNA
synthesis in studying the processes whereby DNA is synthesized
and packaged into a completed virus particle, studies that have
combined genetic, enzymatic, and electron microscopic approaches.
Dr. David Hogness (Biochemistry), whose previous work had been
on the genetics of lambda phage, has focused his undivided attention
in the last two years on the molecular structure, regulation and
expression (developmental) of polytene chromosomes of
Drosophila. Dr. A. Ganasan (Genetics) has been studying the
process of DNA replication in prokaryotes, and more recently
in animal cells, centering his studies on the potential role of
nuclear membrane- chromosome complexes in DXA replication.
Dr. David Clayton (Pathology) is concerned with the synthesis
and function of complex forms of DNA associated with
mitochondria of malignant cells. Dr. Paul j erg (Biochemistry)
has made important discoveries concerning the structure and
function of RNA polymerase, the mechanism and regulation' of
ammo acid _a.ctivation imcf protein synthesis in prokaryote"s. "Not
directly associated witH'the "medical school, but' an active
intellectual input to the work going on .here is Dr. Charles
Yanofsky's group (Biological Sciences), whose studies on the
regulation of the tryptophan operon in E. coli has been pioneering
and one of the most germinal in the field of regulatory biology.
Dr. R. Schimke (Pharmacology) has been concerned for a number
of years with the mechanism and regulation for continual synthesis
and degradation of cellular proteins of animal cells. Dr. Oleg
Jardetzky (Pharmacology) is studying dynamics of protein folding
and molecular interactions of DNA and regulatory proteins, spec
ifically the lac represser, by various physical techniques, including
NMR spectroscopy.

ii) Regulatory Processes-including Developmental, Environmental,
and Hormonal Influences

Dr. Arthur Kornberg (Biochemistry) has been studying
the simplified developmental system of sporulation in B . subtilis ,
a process that involves degradation of cytoplasmic proteins, and
the formation of an essentially "new cell type, the spore. A number
of individuals at Stanford Medical School are concerned with various
aspects of regulatory processes, particularly those that concern
developmental and hormonal-controlled processes. Dr. R. Schimke
(Pharmacology) is investigating steroid hormone regulation of
cytodifferentiation and function of chick oviduct with the eventual
goal of isolating all regulatory components concerned with specific
protein synthesis, i.e. genes, mRNA , protein synthesis factors,
etc. and analyzing their response and behavior with respect to
developmental and hormonal stimuli. Dr. Aronow (Pharmacology)
has been examining the effects of corticosteroids on animal cells
in culture with a view to defining the mechanism of that control
system. Dr. Merton Bernfield (Pediatrics) is also interested
in hormonal regulation of development, and is specifically studying
the role of alterations in isoaccepting tRNA species in the regulation
of specific protein synthesis in chicken liver. Another aspect of
his studies is related to the role of epithelial-mexenchymal

'suop3an°D I^P^S 3°

212

interactions in control of differentiation. Dr. Lawrence Kedes
(Medicine) is studying the regulation of histone synthesis in
the developing sea urchin, and in particular is utilizing techniques
to isolate labeled mRNA for hi stone biosynthesis, to map the
hi stone genes on the chromosome, and to study the activation
of these genes during early emryogenesis. Dr. Frank Stockdale
(Medicine) actively studies the hormonal regulation of mammary
gland development, and the molecular events involved in myogenesis
Dr. Stanley^jpphen (Medicine) has made important contributions
to ouf~uft'de"r stan ding of the mechanism of developme_nt_of_resistance
to a number of antibiotics b y ~a c qui s itfon~bf "d ru g resistance" factors .
He, as well as Dr. Korn's laboratory (Pathology), have made detail
ed investigations of the regulation of episomes, replication and
transfer and its bearing on drug resistance and other pharotypic
properties. Dr. Eric Shooter's group ha.s had a strong program
on analyzing the structure and function of the nerve growth factor;
(NGF) ; 2\GF is a protein of animal origin which specifically
stimulates outgrowth of fibers from embryanic sympathetic
ganglia.

An Institute program in cancer biology will need
considerable development in a number of areas related to
macromolecular structure and synthesis. There is particular
need for a group of investigators who are capable of studying
the molecular structure of proteins and nucleic acids, including
X-ray crystallography and sequencing of both proteins and nucleic
acids. Facilities and expertise for these approaches, so
fundamental to an understanding of regulatory processes, is
totally lacking at Stanford. Other areas to be developed include
the general area of regulation of DNA replication in animal
cells. Programs should also be developed in the area of the
structure and function of animal chromosomes, including the
methodology for isolation of specific chromosomes and the analysis
of DXA -protein interactions by various physical and biochemical
techniques .

Another area of research which is an integral part of a
cancer biology program and should be expanded at Stanford
concerns the structure and function of intracellular organelles.

CELL ORGAXELLES

I. Recent advances in the biology of mammalian
cells have shown that is is quite feasible to study the various
organelles of the malignant cell as separate entities. In
particular, cell membranes, microfilaments and mitochondria
have received increasing attention in the last few years. From
these investigations it is clear that such systems are fruitful
areas to pursue fundamental problems in mammalian cell
Biology.

The specific areas currently under investigation by existing
Stanford faculty are as follows:

Xjis»Aiuft puojirejs 'suop»n<O
sin man uotssiuuad sarmbai uonanDoidai jatnm j -Xruo asn aauaraiai JDI si

213

genome in human tumor cell populations taken at biopsy. This approach tits
in closely with the proposed Human Cancer Cell Bank described in
section E. In Hayflick's program human diploid cells will be used to
determine whether several different oncogenic viruses including
feline and murine sacoma and leukaemia viruses can, under special
conditions, transform these normal human cells to cells having cancer
properties. These special conditions include:

a) Extremely low virus multiplicities, coupled with the
addition of specific immune serum.

b) Transformation of human diploid cells will be attempted
utilizing a combination of very low level radiation and
addition of low multiplicities of several oncogenic RNA
viruses at several times post-irradiation.

c) Transformation of human diploid cells are being attempted
using very low multiplicities of several different human
viruses plus reduced temperature of incubation.

d) Attempts to transform normal human cells with chemical
carcinogens as a means of comparing cell susceptibilities
to viral chemical carcinogenesis; i.e. the compounds of
3 methylcholanthrene and benzo (c )-pyrene.

3) Dr. :?aul Berg's group (Biochemistry) has an expanding and extensive
research program on the Molecular Biology of the DNA Tumor Viruses .-
Polyoma (PY) SV40 and adeno viruses. Their work is proceeding along
the following lines:

a) Identification of viral genetic functions for both lytic growth
and cellular transformation leading to oncogenic potential

in animals.

b) The mechanism and regulation of expression of these genes
particularly the intsrplay of the host cell's and viral regulatory
systems on each other; i.e. how viral genes perturb cell's
growth regulatory machinery and how cell's regulatory systems

— l^m^LB__i__^_^^___im*Jt J«' '"l-'tl .11 mi r ill irji jf ni-i.*.

affect readout of viral gdnes.

214

c) Identification of viral transcripts and the protein products
produced in infected and transferred cells.

d) In vitro analysis of virus-directed processes in sub-cellular
systems; i.e. nuclear and enzyme preparations.

e) Development of a system for viral mediated transduction
of genetic information from one cell to another.

4) Recently Dr. George Stark (Biochemistry) has begun a program to isolate,
characterize and define the function of the T-antigen produced in cells
transformed and carcinogized by these PY ad'SV40 viruses.

5) Dr. William Robinson's program (Medicine) is directed at the Molecular
Biology of the RXA Tumor Viruses particularly the avian group. These
are the best known and so far most intensively studied. Dr. Robinson has
already made numerous important contributions to our knowledge of the
structure of the viral RNA genome, of the GSA and the Type specific
envelope antiger.s. He is currently studying the synthesis of these

viral- specific components in transformed cells as well as the nature
and activity of the newly discovered RNA-dependent DNA polymerase.
Quite clearly this system has been germinal in directing attention to
the possibility that the RNA tumor viruses may well be important for
understanding human cancers. Certainly many of the observations with
the avian system has had direct relevance to the C-type viruses of other
species.

It's cuite clear that there is significant activity now going on
at Stanford in this field of research. What is needed is an expansion
of these activities particularly for increased efforts on genetic approaches
to the RNA Tumor Viruses and for work with other mammalian RNA Tumor
Viruses (feline, murine, etc. ) Even more gaping in our inadequacy is
work with other animal viruses. There presently is no substantial work
with pox viruses of the reovirus type. All of these provide fertilization
for work on the frank tumor viruses. We have little or no ongoing work
with Herpes virus yet this class has recently been implicated in naturally
occurring human as well as animal cancer. As pointed out in another section,

215
STANFORD UNIVERSITY MEDICAL CENTER

STANFORD. CALIFORNIA 94305

I ,

\RTMENT OF BIOCHEMISTRY PAUL BERG

Jack, Lulu and Sam Willson
Professor of Biochemistry

February 29, 1972

Dr. Michael Stoker
Imperial Cancer Research Fund
P. O. Box 123
Lincoln's Inn Fields
'London, W. C. 2, England

Dear Michael:

So often in the last few weeks I've wanted to write to you but an avalanche
of deadlines, from which I am only recently recovering, forced delay after delay.
How are things at ICRF? Hopefully, science, construction progress on the new
labs as well as the many administrative activiii.es you are involved in are going
well; Peter Beard's occasional correspondence with people in the lab and Bill
Folk's visit brought only incomplete accounts of the happenings in London. Right
now I'm wondering how you're faring under strictures oi'-the fuel-electricity
shortage; sounds pretty grirn! Has it caused hardships in the labs, particularly
with being able to maintain necessary services for work and keeping cells
viable and alive0 I suspect that long ago you had seen to ensuring the labora
tories own power supplies and therefore immunity from external exigencies.
From what I read in our newspapers I suspect you probably had trouble
commuting from Kent.

In the last few months things have gone quite well here in the lab. Let
me fill you in on a few of the details.

1) We've mastered the technique of detecting polyoma or SV40 viral DNA
seouences by following the kinetics of annealing using S,, an enzyme which
rapidly degrades single- stranded DNA but leaves double- stranded DNA segments
intact. In a nutshell, (I assume Bill Folk can relay more specific details of
the procedure since he followed our protocols to the letter), we synthesize
very highly p'--labeled PY or SV40 DNA using pure E. coli DNA polymerase
highly purified unlabcled Form I DNA as template--* four very hot d-triphosphates
(10-15 mc/i-mole) and traces of DN'ase to generate random single- strand nicks
in the supercoils. DNA polymerase replicates random segments of the DNA
(by "nick-translation") thereby generating highly- labeled viral DNA segments .
The labeled DNA which has an average single- strand length of 300-500 bases
and a specific activity of 5 - 10 x 10° cpn-i/p-g is used as the "probe" for detecting
complementary sequences in cellular DNA's. The experiment is quite simple
now; e.g. P -PY DNA is denatured in the presence of either salmon-sperm
DNA, BHK DNA or the DNA from cells abortively or stably transformed by PY.
Salt is added to the appropriate concentration (0. 2-1. 5M depending on the rrxte
of annealing wo expect) and annealing occurs at 63°. Samples are periodically
withdrawn, diluted and frozen. When enough samples have been taken, they
are all digested briefly with S^ and then precipitated with TCA. The amount of
annealed DNA is equal to the amount of P"""- label precipitated by TCA and re-

t-;iinr>r! on thi' filter. At y.r-rn tim.= iliics ?_.!<'',. nT t>ir> irmnl af tl-io «=>nd of tVu»

216

Dr. M. Stoker
February 29, 1972

Page Two

70-80To of the DNA is insensitive to S,, (the remainder is probably the fraction
of DNA nucleotides which cannot enter into helical structure because of steric-
hindrance, or we believe more likely, the non- viral DNA sequences carried by
our polyoma stock). The protocol, computer printouts of the data and calculati
as well as the photographs show a typical reconstruction experiment when know
quantities of cold PY DNA (sheared to same size and denatured) is added to the
annealing mixture. Recently, we've simplified this procedure so that samples
are taken only during the first few hours of annealing and cur computer prograr
computes the second-order rate constant (and thereby Cot 1/2) from the initial
points. The second set of computer printout and plots use only the data for the
first 24 hours and. you can see that the curves are linear (2nd order) even with
the points for the first two hours. The sensitivity seems to be good enough
to detect 0. 5-1 genome equivalent per cell (< 1 part in 10°) using approximately
1. 5 to 2. 5 mg of cell DNA.

Using this method we:ve begun to analyze some of the abortive and stab]
transformants of EHK we collected when I was in London. Summarizing:

c •

a) p--FY DNA in the presence of salmon sperm or 3KK DNA anneals
with an identical Cot 1/2: Martin claims that 3T3 does contain some sequences
homologous to SV40 but we shall have to do this mar.y time 3 before one can say
definite!-,- that there is or is not a fraction of a PY genome equivalent in normal
BHK cells.

b) The abortives MA- S (rnethccell) and SA-10 (surface-infected) have no
detectable PY sequences. Of the two stables, transformar.ts we've tested, ST-
and MT-1, only MT-1 contains PY- DNA sequences. (MT-1 3-5 viral equivalents
ST-1 < 1 viral equivalent /cell). Consequently, ST-1 may be a spontaneous
transfcrmant but it should be retested. If you have another sample of ST-1
withpne that can be screen hopefully, one that could be tested for T-ag, we'd
like to retest it.

c) We have just finished growing MA-4, MA-6 and MA- 9 and SA-2 as
\VQ'.' :-.s one other stable trarisformant and will do the annealing kinetics with
their DNA's shortly.

In view of Smith _e_t_ a_L finding with the SV-3T3 abortives it really is
important to determine for sure if PY-BHK abortives really do not have PY-
DNA sequences in their DNA. If there is a difference it could be very relevant
to the mechanism of integration- excision with eac*. virus. It seems crucial
therefore, that we look at as many true abortives as possible to be sure. I hav>
only some of the clones we picked. Do you have more? Or even abortives coll
in different experiments over the years? Or do we have to do another experim
collect a new set (clones grown from microcolonies picked from methocell wou
seern to be the best since they are most likely abortive). I'd be delighted to
come over again to prepare a fresh lot but that's not possible now. Some time
in September (Renato has been trying to talk me into coming when he's there ir
Sept. ) would be possible but that seems a long way off; until them is it possible
to get anv abortively transformed clones, (either ones we collected in 19"0 or

s3Lrejqr[ XjiswAtufi pjojirejs 'suonoanoD

217

Dr.M. Stoker
February 29, 1972
Page Three

any others you have) to look at? Accumulating enough cells for DNA isolation
is a limiting factor since our large-scale growing facilities are still primitive.
Is it possible for your set-up to produce about 5 gms wet weight of some of the
clones0 If we could grow some and you could grow others that might speed
things up somewhat. Unfortunately, although we are in good shape to do the
hybridizations easily enough we are in worse shape to generate and grow well
characterized abortives.

2) Our project to insert new segments of DNA into the SV40 DNA molecv
has succeeded and now we hope to get to sorrre interesting experiments. Without
'going into detail here, unique SV40 linear DNA molecules (made by a single
double- stranded break with a bacterial restriction enzyme coded for by the
drug- resistance transfer factor RTF-1) have been derivatized at their 3 'OH end
with either short runs of dA or dT and after annealing to produce non-covalent
dimer circles they were covalently joined with DNA pciymerase and DNA ligase
to produce sealed dimers in 25-35fo yield. Using the same kind of SV49 DNA /
linears and appropriately derivitized linear DNA from \cygal (mol. wt. 6 x 10
containing about 4 x 1C" daltons of X DNA and about 2 x 10° daltons of E. coli DN
including the entire gal operon), covalently joined hybrid DNA molecules have
been made in about 20-25% yield. Still to be completed (this has run into more
difficulties than I anticipated) is the insertion of a short piece of synthetic
DNA, dl, G:dC (100 base pairs), into the SV40 ring at the R. restriction site
and ultimately at other sites in the structure. Hopefully, such molecules may
give us a way to map the genes of SV40.

There are several other projects moving well enough (Peter Beard's
work is coming along quite nicely) but more about these at some future occasion
either here, in London, or at least by mail.

I do lock for'.vard to your comments on the question of the abortives and
c: course to hearing something about your c\vn work on the serum factors, as
well as of other happenings from ICRF.

Jv'y very best wishes and regards for the coming year to your family,
and colleagues at ICRF. Please remember me to all.

Sincerely,

PB/1

XiiswAiun nionnnc 'suonosnon mo*k jo

218
STANFORD UNIVERSITY MEDICAL CENTER

STANFORD. CALIFORNIA 94305

IEPARTMENT OF BIOCHEMISTRY PAUL BERG

Jack, Lulu and Sam Wilbc
Professor of Biochemistry

March 28, 1972

Dr. Michael .er

Imperial Cancer Research Fund Laboratories

P.O. Box 123

Lincoln's Inn Fields

London, England

Dear Michael:

Your secretary wrote me of your visit to the States; I hope that
you feel welcome enough at Stanford to let me know when you're within
striking distance of Palo Alto so that we can arrange for a visit. We've
come a long way since your last visit but more importantly we'd love
to see you again.

It's really marvelous that you're able to resurrect more of the
abortives and stables and to send us cells for the DNA preps. We have
trypsinized the cells, quenched with serum and washed 1 time by
centrifugation with Tris- saline and then frozen the cell pellets. If we
got the cells you indicated that way it would be great. With respect to
ST-1, we are repeating the determination with another batch of DNA and we'll
do it with your cells as well; that should give a pretty definitive answer.
As you say, if they remain transformed without having the viral DNA that
would be interesting. Do you have anti PY-T serum? It could be important
to know if ST-1 is T-ag~ or T-ag~.

I spoke to Helene Smith last week and she passed on some additional
information. The hybridizable SV40 DNA in one of their isolates sediments
with the cell DNA in an alkaline sucrose gradient done according to Sambrook
_et al. She can detect "no:i infectious SV40 DNA in such cells. Presumably
then it is "integrated". But in one of their clones, the one which gave variable
amounts of SV40 sequences in different clonal isolates of the original abortive,
and on different trials, contained no SV40 DNA after growing up a large batch
of cells. Very strange indeed. The abortives that contain DNA show about
1% of the transforming efficiency of normal 3T3 with. wild- type SV40 DNA
virus. Didn't you find that BHK abortives could be transformed at normal
efficiencies when challenged with PY?

We plan to make highly labeled P -SV40 DNA for use in detecting
SV40 sequences. The .procedure would be the same as for PY; purified SV40
Form I is used as template instead of PY I in the DNA polymerase reaction
and that generates that reagent for annealing. We could test Warner's clones
when they're ready.

We've just had another set of interesting results you might like to
sauBjqn XjMJSAiun pwju^S 'suoposnco FP*Js P waunredsQ

,i,rttT .tniccTiiifvf eaTinhai unmrmo irfoj JOirun J 'XlUO 3ST1 3311313131 JOJ SI XdOOOlOIM

219
Dr. M. Stoker

Page Two
March 28, 1972

hear. -One of my students, John Morrow , has been studying the action of
the restriction enzyme, Rj (coded for by the Resistance Transfer Factor I,
RTFT, carried by E. coli) on SV40 DNA. This enzyme has been purified
by Herb Boyer in SF who gave us some for these experiments. RT cleaves
SV40 Form I DNA (prepared from plaque purified virus) quantitatively to
unit length linear molecules; the distribution of lengths (as seen in EM) is
within 2% that of the circles. Each single strand is unit length in alkali
so quite clearly the enzyme makes only a double- strand cleavage and no
more. The molecules are unique; when denatured and then renatured they
produce only linear molecules with the same length distribution as the starting
molecules. Had they been circularly permuted linears or even two or
several types such denaturation- renaturation produces circular molecules
(the result found with linears produced by PT or B- restriction enzymes or
with DNA'ase). Further proof of the uniqueness of the brea^is the following:
Delius, at CSH, has found that T4 phage gene 32 protein binds to SV40 DNA
Form I and if fixed to the DNA with glutaraldehyde and then spread on grids
for EM inspection one obtains molecules with a single " bubble. "

If such molecules are treated with RT one obtains linear molecules with
a bubble at only one location;

about 40% in from one end. Thus we can differentiate one end from the other.
Most recently, John has done the following; if Ad2-SV40 ND,, the non-defectiv

hybrid of Ad 2 and SV40 DNA (which, according to Lewis contains the ''U-ag
gene" of SV40 covalently integrated into the Ad 2 chromosome) is denatured
and renatured with wild-type Ad 2 DNA one can observe the following
heteroduplex in the EM.

• * I

;«*vj \t - .» -S'^tv u?,-l ^ . Q(

There are two single- stranded (indicated as dashed lines) loops about 16%
in from one end; one segment (a) is longer than the other. If SV40 Rj
produced linears are included in the denaturation- renaturation mixture and
the product is spread on grids one sees another picture:

LUOJJ uoissiuusd saanbai uoponpojdaj jaqun j -A juo ysn xniaujai jpj si Adoooioqj

220

Dr. M. Stoker
March 28, 1972
Page Three

The shorter segment of the loop now appears double stranded and from it
comes two single- stranded tails. The length of the tails and the paired loop
is about equal to an SV40 length. Thus the R, restriction enzyme makes
a break near the U-ag gene. There is some reason to believe from other
Ad 2-ND viral DNA's that the TSTA and T-ag genes are on the longer arm
of the SV40 segment.

I'd like very much to come to London for a bit in September . If
you're going to be there during the first three weeks or so it would be
fun to come over and try to do some experiments. Will you be moved
into the new labs then or is that just about the time you'll be moving in?
I'll keep in touch with you about how things are going on this and other
projects. If you know of any appropriate conferences or meetings in
England or on the continent in the Fall, please let me know.

So much for now. My best to all at ICRF and to Veronica. Peter
Beard is doing very well and I'm delighted at his being here. He's made
several very interesting findings that are proving very useful; he sends
his regards to all.

PB/1

'suop:»n<O

221
STANFORD UNIVERSITY MEDICAL CENTER

/ STANFORD. CALIFORNIA 94305

EPARTMENT OF BIOCHEMISTRY PAUL BERG

Jack, Lulu and Sam IVillsoi
Professor of Biochemistry

June 19, 1972

Dr. Michael Stoker

Imperial Cancer Research Fund

P.O. Box 123

Lincoln's Inn Fields

London, W. C. 2 England

Dear Mike,

Another progress reportl Marianne has, Lbelieve, already let
you know that the cells arrived in good shape and she will work them up
soon to isolate the DNA's for testing. Thanks for making that part of the
experiment easier.

Meanwhile we have run through a few more clones and repeated the
annealing kinetics with the older ones. The results are quite consistent
and give the same result (Table I); none of the abortively transformed
BHK have any trace of PY DNA I In Cot #17 the Cot1/2 w°uld have decreased
by a 2-fold if the cell DNA had contained 2. 5ng of viral DNA; assuming the
diploid cell genome size is ^SxlO1^ daltons of DNA, halving of the Cotj/2
would have indicated 1 viral genome/cell. In Cot #20 we increased the sen
sitivity so that 1. 2ng of viral DNA in 2. 5mg of cell DNA would have halved
the Cot 1/2' As you can see except for clone MT- 1 there is no substantial
homologous sequences in any of these abortives. ST-1 (our batch of cells)
is puzzling; one could argue that it has about <5l0.5 a viral equivalents but
I don't know whether to believe it. "We are repeating it with DNA isolated
from the ST-1 you just sent us (and which you said is T-ag negative although
morphologically transformed). We plan to run through the rest of the abor
tives and stables we have to get more numbers but then there is the question
of interpretation and what nextl

If the result is real (and I tend to believe it at this point) and Smith and
Martin's result for SV40 abortively infected cells is also correct, then what
is it trying to tell us? Is it that the steps and mechanism of transformation
by the t%vo viruses in these hosts is different? Conceivably in PY the inte
gration-excision function (ts-a?) is expressed all the time, both in the "free"
and "integrated" state so that a DNA molecule is constantly integrating and
excising. Stable transformation occurs only when an integrated genome
can't be excised (even though excision "enzyme" is present) or when a genome
with a defective ts-a function is integrated and there is a lack of helper par
ticles to complement its excision. In short, wild-type particles can't remain
integrated iznless aberrent insertion) but DNA's with a defective ts-a function
(as for examples Mike Fried' s ts-a itself at high temperature) remain inte
grated. This model is quite consistent with Vogt and Summers' and Bill Folk's

r»»r»Tinnc> 'cuonTsn<v\ nnr>a(c TO

<Dr. Michael Stoker 222

Page Two

•

recent findings on the "inducibility" of ts-a transformed BHK. In one sense
BHK may not be any different than mouse cells except for the inability to
multiply the virus. That is, PY BHK is like PY-3T3 and ts-a-BHK is like
ts-a-3T3 except that 3T3 is permissive for extensive replication.

What about SV40 infection of 3T3? Perhaps in this instance the
integration-excision function is inactivated as a result of integration; that
is, integration shuts off expression of the gene controlling the excision
function. Thus when growth of the cell dilutes out existing enzyme and help
er particles, the integrated genome becomes "locked in'1. Fusion with per
missive cells could activate the excision function and permit replication to
occur.

It's quite possible that there are clones of abortively transformed
BHK that do contain PY DNA but these might be rare and represent only
that class in which either the excision function was defective or the mode of
integration was abnormal; in either case the transformed phenotype would
have to be "repressed".

The only way I can think of to test this model is to look for curing of
transformed cells. I used to think it was best to do this by superinfecting
PY-BHK with PY (at high moi) and to see if substantial numbers of non-trans
formed clones are produced (infection should catalyse a new round of excision-
integration leading to a new stable state, about 5% transformed cells). We
took a try at this but the attempt was crude, being done with only one strain
of PY-BHK; we have not done more. But now I think it should be tried with
SV3T3 superinfected with SV40 at multiplicities which cause good "abortive
transformation" I shall approach Helene Smith about doing that experiment.

What do you think? and what do you suggest we do further with the
analysis of the PY-BHK abortives? Is it worthwhile making another batch
of abortives to test? That would take time but maybe it should be done to
nail the point down. Perhaps one should use mutagenized PY or preps en
riched for defective virus. Conceivably one could reduce the excision process
and thereby hope to produce abortives that contain viral DNA.

Are you going to be in the States this summer? At the Tumor Virus
meetings in Cold Spring Harbor or at a Gorden Conference? Or is the only
way we can discuss this or plan something for me to come to London for
awhile? I turned down going to the Brighton Cell Biology meeting (thanks for
suggesting my name to them as a speaker) because the first two weeks of
September was a very bad time for me to be away. If you're not going to be
in the U.S. do you believe it would be worthwhile for me to come during the
second half of September for long enough to review and discuss the experiment
and how to proceed from here. (Unfortunately I don't think I can stay long
enough to do any serious experiments. )

Now for other news. You may recall that I wrote you about the Rj restri
tion enzyme making one specific double- strand scission of SV40 to create a
unique length linear molecule. We've used that molecule now to locate the
SV40 segments carried by Ad2-SV40 hybrid ND-1, ND-4 and E46+ along the
Rj linear.

I Dr. Michael Stoker
Page Three

223

(1) For example the Ad2 x Ad2-ND-l heteroduplex looks as follows:

2. *fc«*»« d«.W*A fr— ' NO-t

>cw. •i\.'.jc-<-C TTtv»

and the heteroduplexes formed by Ad2 x Ad2-ND-l x RT linears of SV40
looks like

"foopW A$tf*0

-MtH*.* R'1'

the short arm (0.1) plus the short
duplex region (0. 16) and the long arm
(0. 74) equal one SV40 length.

(2) The Ad2 x Ad2-ND-4 heteroduplex is as follows:

and the corresponding Ad2 x Ad2-ND-4 x RT linear is

According to Lewis and Kelly the AD2-ND-1 induces U-ag while
Ad2-ND-4 induces U, TSTA and T-ag. Moreover they say that little or
none of the late SV40 genes are carried in these hybrids. Therefore it
follows that the Rj restriction enzyme cleaves in one of the "late" genes
of SV40 perhaps one of the capsid structural genes. One could draw a
tentative "genetic map" of SV40 (not to be taken too seriously) as follows,
The actual boundaries of

.ate | U

TSTA T-ag
t l i

Late

) 0. 1

0.26 0.43 0.53

0. 1

rj Xji\»Aiun puojinns *suo

JDr. Michael Stoker
Page Four

pre^-iMi. ^Oci-^a 3«*»<i OT ~tlx

TheAthree putative genes are unclear although the order seems to derive
from the fact that ND- 1 induces U alone, ND-2 induces U and TSTA but not
T and ND-4 induces all three antigens. It is interesting that the segment
assigned to late genes is enough to code for about 70, 000 daltons worth of
polypeptide which would account for the two chains 40, 000 and 30, 000 that
Renato says comprise the capsid.

The heteroduplexes with E46+ are more complex but consistent with
this model. The difference is that the SV40 segment integrated in the E46"1"
hybrid has a deletion of the Rj restriction site but the early genes appear to
be contiguous.

The most recent finding which excites us is that Rj makes a staggered
break, i. e. , I in which the number of bases between

breaks is of the order of 6i2 (probably six). Thus the linears can be circu
larized at low concentration at 3-5°C and can be covalently sealed with DNA
ligase to regenerate completely infectious and full length SV40 molecules
(actually the linears are one-tenth as infectious as wild-type probably because
the cell itself can'blose the ring"). It seems very likely that the site at which
the enzyme cleaves is identical in all DNA's (it occurs on the average once
per 4, 000 bases in a random sequence) and very likely is summetrical.

i -J

- i^A B C C' B1 A' -

- A1 B' C' C B

We can show experimentally, that any two DNA molecules having ends pro
duced by RT endonuclease can be covalently joined. In other words the ability
to construct molecular hybrids is enormously extended. We have now to find
out how to deal with this intelligently.

How is the work going on the serum factors? Is it possible to assign
specific cellular functions to specific serum proteins yet? You must be just
about getting ready to move to the new quarters. Good Luck. I envy Art
Pardee his next year.

Well so much for now. I look forward to hearing from you about PY
abortives. As we get more data I'll keep you in touch. I'd appreciate it if
you could pass some of this scientific information along to Bill Folk and any
body else you care to so as to save me the time of writing it to him.

With best regards to all at ICRF and to Veronica.

Sincerely yours,

~. ,£ )

PB:af

rmnirfai t3inm j 'Xnio a»n mroEJiai jm <n

for. Michael Stoker
T>age Five

P.S. I wonder if I can make a request of you. So far we've been using
one of our PY virus stocks to prepare the p-^2 DMA for annealing. That's
not the same one we used to do the infections of BHK. I don't believe that's
serious but perhaps we should make some DNA from your stock to be sure.
More importantly our virus stock must surely contain defective particles
containing insertions of host DNA. This slightly complicates the kinetics of
annealing (because the host sequences probably don't anneal with the same
kinetics as the PY sequences). If your stock is plaque purified or if you
have a plaque purified stock from which you could let us have enough to make
a batch of DNA (from infected mouse kidney cells) that would be very help
ful. Otherwise we shall have to take the time to make such an isolate and
that would be time consuming.

puojirns 'suoiKwn°D (toads J° nwumwfaQ

226

TABLE I

Cell DNA's tested

Cot #17 Cot #20'

Normalized Cot. ,.,

Salmon Sperm

BHK

SA-2

SA-10

MA-4
MA-6
MA- 8
ST-1
MT-1

2. 1 x 10

-3

2. 1 x 10

-3

2.0 x 10

-3

1.9 x 10
1.6 x 10

-3

0.6 x 10

-3

1.3 x 10'

1.3 x 10
1.9 x 10

1.4 x 10
1.3 x 10

1.3 x 10

1.4 x 10
0. 9 x 10

-3

1. Cell DNA's were added to the annealing mixture at a concentration
of 50A26Q (2«5mg/xnl); it was sheared to average single-strand
chain length of 400-500 bases.

2. In Cot #17 the 32P-PY DNA was at a concentration of 5 x 10"5A260
(2.5ng/ml); average chain length of DNA was 400-500 bases.

3. In Cot #20 the 32P-PY DNA was at a concentration of 2. 5 x 10~5A260
(1. 2ng/ml); average chain length same as in Cot #17.

an UJQJI uoissiuuad sannbai uoncmpoidai JTUUTI 4 'Xruo ?sn xniaiaiai jpi si

Photocopy is for reference use only. Further reproduction requires permission from the
Department of Special Collections, Stanford University Libraries

227

March 27, 1973

Dr. Norman K. Wet selli
Department of Biology
Stanford University

Dear Norm,

-. I want to nominate Miss Janet Mertz.for this year1*

Francis Lou Kail man Memorial Award. It's zny view that
Janet i* one of the beet graduate students presently in our
department; in fact* I would rank her amongst the top five
students we have ever had in Biochemistry. She is one of
the hardest working, brightest and most creative young
people I have ever worked with. Moreover, she has that
rarest of talents: things get done no matter the difficulties
encountered. I predict a very bright and productive scienti
fic career for her future.

Janet came to our Department in September of 1970
with a very distinguished undergraduate record from MIT;
she completed a double major in electrical engineering and
biological sciences in three years with* as I recall, almost
a straight A record. The enthusiasm with which we accepted
her has not diminished one iota.

From the day she began research her progress has
been most impressive. Her project was to examine the
possibility of isolating deletion mutants of SV40 virus and
with these to locate the genes coding for the different viral
functions. With almost breathtaking speed she mastered the
available literature and set about acquiring the cell culture
skills needed to begin her experiments. I was astonished at
how rapidly she mastered these techniques and how frequently
•he came up with improvements in our standard procedures.
Now, she is one of the "experts" of our group and I would
count heavily on her abilities to train newcomers to the lab.

,~ .*

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228

Dr. Norman Wes cells
Page Two

Janet has virtually completed three publishable and
quite significant researches.

1) Together, with Ron Davis, she discovered that the

RI restriction endonuclease catalyzed cleavage of DNA generates
identical and cohesive ends; this makes it possible to reseal
the ends of a circular molecule cleaved by this enzyme or. more
significantly, to join any twoJjN A molecules or fragments having
such termini (see'enclosed'reprint)^ (Yanofsky is presently
using this approach for joining the tryptophan represser gene
to a p Las mid form of X DNA so that the number of copies of the
represser gene can be increased in cells made to carry that
plasmid. ) Her presentation of this work at the Tumor Virus
Meeting at Cold Spring Harbor created quite a stir.

2) Together with one of Dale Kaiser's postdoctoral
fellows, Doug Berg, whe prepared and isolated what has turned

/ out to be an extremely useful new type of genetic structure:
Xdvgal. In this structure the gal operon of E. coli has been
fused into a small DNA plasmid containing about 7% of the X phage
genome. These molecules can be propagated in E. coli cells as
episomes (about 50.100 copies per cell). Janet modified and
improved an assay system for introducing the pureXXdvgal DNA
into virgin cells to reestablish the episomal state. This system,
therefore, provides a way of introducing new genes into E. coli;
by covalently joining any piece of DNA to the Xdvgal DNA, it
can be introduced and stabilised in the recipient bacterial cell.
This ability has paved the way for Dave Hogness* group to
attempt to clone Drosophilia DNA segments.

3) Janet is now well along in the main part of her thesis
research: The isolation and characterization of deletion mutants
of SV40. She has already prepared and characterized stocks
with a variety of deletion and substitutions at various locations
in the SV40 genome. In doing this she has become an expert and
sophisticated electron micros copiat and with this technique has
carried out an elegant analysis of the heteroduplexes formed
from deletion* substitution mutant DNA'* with wild-type molecules.
Her next immediate goal is to clone these and to characterize the
specific genetic defect each type of deletion produces.

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229

Dr. Norman Wes sells
Page Three

Let me say in finishing that Janet is one of the most
eager student teachers we've had. As a first year student
she volunteered (she was the only one to do that) to supervise
a section of almost 15 students in our Biochemistry 201 course.
The following year she participated in literature discussions
with another group of Biochemistry students. She generally
gives some of the best seminars in courses or in Departmental
meetings. Her performance as well as her research has
already attracted considerable attention at several National
Meetings.

In summary, then, let me say that I know of no student,
let alone any woman student, that I feel more confident about
in nominating for this recognition. She has certainly earned it.

Sincerely yours,

Paul Berg

Professor and Chairman

PB:af
Enc.

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230

September 16. 1975

Dr. William J. Rutter

Department of Biochemistry and Biophysics

University of California

San Francisco, California 94143

Dear BUI.

I'm delighted to be able to support your recommendation
that Hejrb^Bovjsr be promoted from Associate Professor to full

ProfeTTort"*

Herb's contributions over the past five years on the mechanisms
of restriction and modification of DNA by microbial and phage enzymes
have been outstanding. His work combined elegant genetic experiments
with enzyme studies to sort out the kind of relationships which charac
terize the restriction-modification specificities.

About two years ago his work took another and, I believe, more
original and germinal line. This was to isolate purified restriction
and modification enzymes, to characterize the nature of their cleavages
and modifications chemically. During these studies two enzymes (EcoRI
and EcoRII) which had been discovered and purified in Boyer's lab were
found to have remarkable properties: they cleave both strands of DNA's
lacking the appropriate modifications at specific p%lrmdromic sequences
so as to create cohesive ends. Not only do these enzymes serve as
site-specific nucleases, making possible nucleotide sequencing of the
fragments but the existence of cohesive ends makes possible in vitro
recombination between different DNA molecules having the same enzyme-
generated cohesive ends. This may well revolutionize molecular
genetics as indicated by the astounding experiment by Boyer and his
colleagues in which they succeeded, in^synthesizing hybrid DNA molecules
containing the 16S, 28S or both rDNA'.'.ot kenopus^ciavaUntly inserted into -*'
tive" circular R factor DNA and to propagate' these molecules in growing
E. coli as aa episomal elements The implications of this accomplishment
are enormous and Herb is actively pursuing many of these new leads.

Boyer's work has had great influence on the newer recognition
that restriction enzymes provide us with a very powerful methodology for
the analysis of the structure and expression of DNA chromosomes of
viruses, bacteria and higher cells. I believe Herb is one of the world's
leaders in the field of restriction modification and particularly in its
application to trther broader problems such as gene expression.chromoson

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231

Dr. William J. Rutter
Page Two

structure. His work in the construction and study of recombinant
DNA molecules will certainly be at the forefront of this area of biology
for a long time to come.

You may recall that I nominated Herb for the 1975 Pfizer Award
in Enzyme Chemistry. That is one measure of the high regard I have
for his contributions.

I should also add that my scientific contacts with Herb have
always been most cordial and helpful. Time and time again he has most
generously given us enzyme preparations, bacterial strains and unpub
lished data. In today's world of "cutthroat" competition, I regard his
behavior as being in the best traditions of open science.

With best regards.
Sincerely,

Paul Berg

Professor of Biochemistry

PBraf

* 232

Testimony by Paul Berg

Subcommittee on Science, Technology and Space
November 2, 1977

Senator Stevenson, I am grateful for your invitation to
participate in this committee's discussion of the current status
of recombinant DNA activities. I particularly value the oppor
tunity to present my views on the fundamental and practical issues
that have been raised in the public debate on recombinant DNA
methods.

To begin, let me introduce myself. My name is Paul Berg
and I am Willson Professor of Biochemistry at Stanford University
School of Medicine. When I'm not distracted by recombinant DNA
matters I conduct research and teach biochemistry and molecular
•biology. My particular specialties are molecular genetics and
viral carcinogenesis, both of which have become increasingly amen
able to and dependent upon the use of recombinant DNA methods.
I have neither a direct nor indirect association with any commer
cial enterprise engaged in, or contemplating, research or manu
facture using recombinant DNA methods.

I am also not a newcomer to the recombinant DNA controversy.
A moment will suffice to summarize the extent of my involvement.
My laboratory was amongst the first to construct, outside of a
living cell, a hybrid or recombinant DNA molecule; hence, I was
one of the earliest practitioners of recombinant DNA research.
Because several friends and colleagues expressed concern about
the ramifications of my experiments I became an early partici
pant in discussions of their potential risks. Subsequently, my
involvement with these concerns grew by being chairman of a commit
tee that warned the National Academy of Sciences about possible
risks that might result from the indiscriminate use of recombinant
DNA methods. I also served as chairman of the committee that
convened and presided over the Asilomar Conference on Recombinant
DNA Molecules; the report of those proceedings to the National
Institutes of Health made specific and novel recommendations for

233
-2-

scientific and administrative procedures that could ensure safe
conduct of this line of research. Although not one of the archi
tects of the NIH Guidelines, I was consulted at various times
during their formulation and prior to their release in July, 1976.

A relevant question with which to begin is why are biologists
throughout the world so excited by the recombinant DNA methodology.
Is it, as some have charged, just fun and games, the chance to
enhance one's career or ambitions or is it to advance genetic mani
pulation of humans for nefarious purposes? I doubt that any of
these selfish reasons 'motivate more than a small fraction of the interna
tional scientific conrnunity. Rather, the overwhelming body of scientists view
the recombinant DNA methodology as an extraordinary opportunity
to solve important biological problems; the knowledge gained
will illuminate our biologic nature and heritage;and very likely,
help to alleviate the tragedies of human disease, starvation and
the pollution of our environment. What are the opportunities, and
important biological problems that recombinant DNA research can
help to solve? Basically there, are three answers:

1) The recombinant DNA methodology permits the isolation of
single or groups of genes in high purity and virtually unlimited
quantities from almost any living organism. Except in special
cases this can not be accomplished by any other presently available
method. Coupled with another new procedure, that is virtually
child's play, the basic chemical structure of these isolated genes
can be readily solved. These two techniques can tell us a great
deal about the molecular structure and organization of the complex
chromosomes of higher plants, animals and man. I described how
recombinant DNA methods were uniquely suited for the task of recon
structing complex chromosomes during my presentation to the National
Academy of Sciences Forum on Recombinant DNA Research last March.
These are not idle speculations. They are realistic estimates
drawn from the impressive achievements so far. There have

also been problems and several surprises; each of the surprises
introduces unexpected subtleties and makes more fascinating
and urgent that we get on with their solution.

2) The ability to join together different DNA molecules per-

234
-3-

in simple as well as complex chromosomes. Together with classical
methods for creating hybrid cells and organisms, one can envision
more sophisticated analyses of the mechanism of gene and chromo
some function. Understanding differentiation, the process where
by embryonic cells containing the identical complement of genes
and chromosomes, gives rise to the myriad cells and organs of the
organism, is a worthwhile and realizable goal. It is difficult
for me to see how that knowledge will not have ramifications for
the treatment and possibly prevention of certain birth defects
and other developmental disorders.

3} The ability to isolate pure genes puts us at the thresh
old of new forms of medicine, industry and agriculture. Tailor-
made organisms produced by recombinant DNA methods could provide
valuable diagnostic reagents, probes for studying the operational
status and efficiency of gene expression in health and disease,
vaccines to immunize individuals and animals against the ravages
of certain bacterial and viral infections and, possibly, even
cancer; and, finally, there is extraordinary progress towards the
construction of organisms that make therapeutically useful pro
tein hormones; the isolation of the insulin gene is a promising
start; the bacterial production of somatostatin, a hormone produced
by the brain is even more astonishing. A joint effort between research groups at
the University of California Medical Center, San Francisco, the
City of Hope in Los Angeles and the Salk Institute in San Diego
has resulted in the production of about 5 mg of somatostatin;
only 100 gms of E.coli , grown in about 2 gallons of culture was
needed. Bear in mind that it took nearly half a million sheep
brains to yield 5 mg of somatostatin in the researches for which
Drs. Guillemin and Schalley received this year's Nobel Prize in Medicine.
Equally significant is the ingenious and elegant way in which
it was accomplished; chemical synthesis of the gene and pro
duction of a modified form of the hormone so that chemical
processing outside the organism is necessary to liberate the. hormone
This approach provides a novel alternative to the previously planned
procedures for producing many such products.

235
-4-

In this brief statement I can only mention but not
amplify, some of the important advances that are being made by
recombinant DNA techniques. If you like I could expand on some
of them in the subsequent discussion. In short, I sense a mounting
wave of accomplishment and progess that give lie to the charge that
the benefits of reccmbinant DNA research are only speculative
and ephemeral, and that only the dangers are real.

Before considering the question of risks I want to say
.a few words about genetic engineering, - the directed modi
fication or even construction of new genetic constitutions for
animals, plants and man. Partly because of the exaggerated
and misleading claims by the popular press and some scientists
and laymen as well, this term has evoked as much alarm as excite
ment. I would guess, that deep down it is what troubles some
people most. But man has been involved actively in genetic engi
neering ever since he came down from the trees, planted maize and
domesticated animals. The animals and plants that provide our
food, the microorganisms that make our bread, beer and wine,
the organisms that make our antibiotics and purify our sewage,
are all subject to our genetic counseling. We have carried out
wars of genocide against polio virus, small pox and plague and
are much the better for it. Recall that for the worst holo
caust in history Hitler did not need science and technology;
ovens and gas chambers did the job. Malnutrition, poor and inad
equate nutrition warps the minds and bodies of hundreds of
millions of infants and children throughout the world and our
personalities and behavior are manipulated and profoundly in
fluenced by the printed page and television. Genetic manipulation,
then, is not, itself, good or bad; we need to distinguish between
the acquisition of knowledge and the applications of that
knowledge and know how to achieve both wisely. Human gene
tic engineering is a concept worth ' examining in rational
ways. It is not at all clear that it is feasible, nor when
it will be, if at all. There are many difficult and
contentious scientific, ethical and moral questions to be examined
and at many stages there will be opportunities by all segments
of our society to have their sav. But preventing or slowing down

236
-5-

basic genetic research now, seems ill-suited to dealing with
that question.

Nov; let me turn to the matter of risks. Three years ago
I expressed concern about the use of recombinant DNA techniques.
There was no evidence that such experiments were hazardous, only
conjecture; but we wanted assurance that these novel experiments
would be safe. More than three years later, after considerable
discussion by experts in this country and abroad and the analyses
of past experiences and new findings, I and others have changed
bur assessment of the risks. I now believe that the possibility •
that experimental organisms will be hazardous or released is
exceedingly small.

Where it has been examined, organisms modified by recombinant
DNA methods are at a disadvantage in competing with their paren
tal or wild organisms. Moreover, certain constructed DNA molecules,
hitherto believed to be novel, can arise in nature by reactions
akin to those used in the laboratory. There is also the virtually
unanimous agreement of experts in infectious disease and epidemiolo
gy that strain K12 , the enfeebled laboratory variant of E. coli
widely used for recombinant DNA experiments, is unable to colonize
normal hunan or animal intestinal tracts. Based on recent experi
ments and existing data, these experts also concluded that there
is little or no likelihood that strain K12 can be transformed
into an infectious or pathogenic organism or even into a human
intestinal inhabitant by a bit of foreign DNA. This view has
been echoed by Rene Dubos one of our most eminent biologists, an
authority in infectious diseases and an ardent environmentalist.
He concluded that "I doubt that gene recombination in the labora
tory will create microbes more virulent than those endlessley
created by natural processes". Moreover, the introduction of
genetically enfeebled derivatives of strain K12 and vectors that
are not readily transmissable to other bacteria, provide a fur
ther measure of safety. Hence, our initial concern that novel and
laboratory-created recombinant DNA molecules could become widely
disseminated to man, animals and the ecosystem is not supported
by the available data. /

Enacting legislation to govern the content and methods of >/

-6-

In my view legislation of the type that has so far been pro
posed would inhibit basic research on important biological and
medical problems. The rules, procedures, and penalties are pre
dicated on assumptions that will surely change, thereby making
it difficult and cumbersome to adjust to the changing information,
ideas and opportunities. I believe that legislation could stul
tify the creativity and initiative that has characterized the
development of the recombinant DNA technique; it could also
discourage and disillusion young scientists from entering this
field. I believe that the present U.S. NIH guidelines, as well
as analogous codes of practice in other countries, afford the
security to meet the perceived risks. Many scientists believe
the guidelines are too restrictive and that most of the pro
scriptions cannot be justified by any scientific information we
now possess. But in spite of their reservations, scientists and
their institutions have accepted the guidelines as an interim so
lution to the anxieties that remain. The acceptance of that view
is a responsible action based on careful weighing of the alterna
tives and rejects irrational fears as a basis for decision.

As I see it, most of us are seeking the same objective: To v
reap the benefits, basic knowledge and practical advances from
recombinant DNA research with a minimun of risk to our world.
.Members of the academic research community are now the principal
practitioners of recombinant DNA research in this country. Since
most of their research is funded by government agencies, it is being
done in compliance with the procedures and administrative mecha
nisms embodied in the NIH Guidelines. The sanctions and con
sequences are severe and, therefore, a strong deterrent to non-
compliance. A question frequently put is •- what about recombinant
DNA activities that are not under the Guidelines' jurisdiction?
But surely there are existing mechanisms that guard the public
against known hazards of pathogenic agents. Are there not exist
ing statutes that could deal with these . hypothetical risks as they
do now with real and documented hazards? If not, we could consid«
establishing a parallel set of procedures and practices, agreed
to by representatives of the private sector and monitored by the
Department of Commerce, to cmidp i nrhist-r ial r^sparch. develooment

238

and production activities using recombinant DNA methods?
Industry's concerns in this area are unique to them; and the
academic research community's concerns are foreign to the world
of commerce. Does it make sense, then, to have both types of
activity operate by an identical set of rules and procedures
and subjected to constraints that are inappropriate to each?
I suspect that just as the consortium . of scientists, the public
and the Department of HEW arrived at acceptable codes of prac
tice, a similar coalition of the industrial sector, the public
and the Department of Commerce could develop an equally accept
able set of guidelines for their activities.

Let me end by saying that I am particularly concerned by the
growing efforts and influence of the anti-science forces. . This
is apparent in the increasing pressures to suppress scientists'
explorations for fear of what their discoveries will uncover or
produce. Decisions and agreements about what is desirable,
acceptable and safe to know are nearly impossible to obtain at
each level of social organization. Deeply held and conflicting
sociopolitical ideals challenge the traditional views of what
science is for and how it should be done. As these forces gain
momentum, there are increasing attempts to restrict scientific
research.

Society desperately requires effective mechanisms for anti
cipating and evaluating the impact of scientific and technologic
breakthroughs. In the recombinant DNA matter scientists demons
trated that they could provide the early warning system for alerting
society to the potential benefits and risks of their discoveries;
accusations of self-interest, arrogance or even malevolence do
little to encourage further efforts of that kind. We may already
have squelched the concerned scientist of tomorrow. Governing
bodies, everywhere, must seek better ways to encourage scientists'
participation and the means to channel their input into the determi
nation of policy.

Perhaps, these poetic words of Aristotle can guide us, scientists and
politicians, in our search for wisdom in these matters.

-8- 239

He wrote:

"The search for truth is in one way hard and
in another easy. For it is evident that no
one can master it fully nor miss it wholly.
But each adds a little to our knowledge, and
from all the facts assembled there arises a
certain grandeur."

Thank you,

—
>,

_, . 240

Photocopy is lor reference use only. Further reproduction requires permission from the

Department oETp^flOIBII^filMi^SEftfidaiIrM6fi^^bi*i^TER

STANFORD, CALIFORNIA 94305

TMENT OF BIOCHEMISTRY PAUL BERG

Willson Professor of Biochemistry

March 5, 1979

Dr. Richard A. Rifkind

Cancer Center/Institute of Cancer Research

College of Physicians & Surgeons of

Columbia University
701 West 168th Street
New York, New York 94305

Dear Dr. Rifkind,

I really wish I had the talent to pick up a dictaphone and provide a
scholarly, comprehensive summation of the state of and opportunities in
molecular genetic research; but I don't. I also wish I had the leisure
to organize various thoughts and opinions on these subjects in a letter,
but, alas, that too is lacking. In fact other pressing obligations that
can not be put off have precedence on my time and energy, thereby necessi
tating a brief reply.

In my view the most promising opportunities in molecular genetics
research for now and the coming decade will be in the area of organization,
replication, expression and regulation of mammalian (human) and other
eukaryote genomes. The emergence of restriction endonuclease and molecular
cloning techniques, rapid DNA sequencing and the ability to prepare mono
clonal antibodies make feasible experimental approaches to many problems,
that were hitherto impossible. I believe it will be possible to reconstruct,
in molecular detail, the gene organization of specific loci (e.g. the loci
governing the expression of the human hemoglobins, the innuno globulins and
HL-A regions are in the offing) as well as extended chromosomal regions.
I also believe we may be able to identify the genetic signals and mechanisms
that govern differential gene expression (e.g. hormone control, and other
homeostatic mechanisms) and possibly to define the general features of
developmental programs. Clearly if that comes to pass the impact on our
understanding of the underlying mechanisms of many pathologies will be
profound. The progress I foresee will enable us to reap the rewards of
the basic molecular biology advances of the last three decades.

Without being exhaustive I would identify the following individuals
as people capable of making giant strides in that direction: David Hogness,
Donald Brown, Richard Axel, Philip Leder, Tom Maniatis, Phillip Sharp,
Charles Weissmann, Pierre Chambon, Richard Flavel, David Botstein,
Ronald Davis, Gerald Fink. Undoutedly there are others but these will
give you an idea of the type of people I have in mind.

Good Luck in your venture,

Sincerely,

241

APPENDIX C

The 1980 Nobel Prize in Chemistry

Three molecular biologists win the prize for discoveries
that can be used to study gene structure and control

The current Nobel Prize in Chemistry
spotlights contributions to the methodo
logical revolution that is allowing re
searchers to examine the structure and
control of genes of higher organisms in a
dc'.'.'' previously nnimngined. Half of the
prize was awarded to Paul Beig of Stan
ford University; the other half was
. awarded jointly to Frederick Sanger of
• Cambridge University and Walter Gil
bert of Harvard. This is Sanger's second
Nobel Prize.

Berg is cited for "his fundamental
studies of the biochemistry of nucleic
acids, with particular regard to recombi-
nj. : DNA." According to a press re
lease from the Swedish Royal Academy.
"Berg was the first investigator to con
struct a recombinant DNA molecule.
i.e.. a molecule containing parts of DNA
from different species. His pioneering
experiment has resulted in the develop
ment of a new technology, often called
genetic engineering." Berg does not
kr.iiw whether the Nobel committee had
a ;-.ir:icu!dr experiment in mind but. he
sav -,. "1 would like to think it [the prize]
was for a body of work and not for a
single experiment. " Arthur Kornberg.
also of Stanford, thinks the only way to
interpret the Nobel committee's "care
fully worded citation" is as recognition
for Berg's 20 years of leadership in the
molecular biology of nucleic acids.

In the 1960's. Berg did a great deal of
ir:.ovative work on bacterial protein
vnthesis. particularly the interaction of
amino acids with transfer RNA's. His
work helped explain how these RNA's
are used as adapters in decoding. His
group and several others also discovered
one of the enzymes that copies DNA into
RNA.

Then, about 10 years ago. Berg and

SCIENCE. VOL. :io. :i NOVEMBER ivso

many other molecular biologists became
interested in applying what is known
about bacterial gene expression to the
study of gene expression in higher orga
nisms. "We began to think of using SV40
[an animal tumor virus] to carry genes in
to m.imma!i;:;i colls," Bcr- v.;<,. Tin-
foreign genes could then be studied and
manipulated to see what controls their
expression.

In 1971, Berg and his colleagues David
Jackson and Robert Symons opened the
circular SV40 molecule with a restriction
enzyme, Eco Rl. This enzyme, which
w;as discovered in Herbert Boyer's labo
ratory at the University of California at
San Francisco, cleaves DNA at specific
base sequences. In the case of SV40
DNA, it cleaves it in exactly one spot.
Berg's group then spliced the linear
SV40 DNA to the DNA of the bacterial
virus \. The X DNA also is circular and
Berg's group cleaved it too with Eco Rl.

Although this was the first time that
DNA's from two different species were
joined, it was not the first time that any
DNA's were joined. H. Gobind Kho-
rana. of the Massachusetts Institute of
Technology, discovered in the 1960's
that an enzyme produced by the bacte
rial virus T4 can catalyze the linking to
gether of DNA molecules. Berg. Jack
son, and Symons enzymatically con
structed complementary or "sticky"
ends on the two DNA segments to be
joined and then used the T4 enzyme to
do the joining. The method they used
was developed and tested independently
by Berg's group and by Peter Lobban
and Dale Kaiser of Stanford. Although
no one knew it at the time, it was unnec
essary to construct sticky ends, since
they are automatically produced when
Eco Rl cleaves DNA. This fact was dis- Paul Berg

0035-8075,80' I i:i-088?S00.50,'0 Copyright C 1980 AAAS

covered in 1972 by Janet Mertz and Ron
ald Davis and independently by Vittorio
Sgaramella. all of Stanford University.

It had been Berg's intention to in
troduce the SV40-A. hybrid molecule into
the bacterium Eschericliiu cnli . which X
c;m infect. In th.'.t wny. he could pet mnn\
copies of the molecule to be used tor
future experiments in gene expression in

88-

woe World Pholo

Frederick Sanger

mammalian cells. In the summer of
1971, Mertz, who was Berg's graduate
student, described the plan at a tumor vi
rus conference held at Cold Spring Har
bor. New York. Robert Pollack of Cold
Spring Harbor Laboratories reacted im
mediately with dismay, pointing out that
SV40 transforms human cells in culture
and that E. coli lives in the human gut. If
any E. coli infected with the SV40-X
DNA escaped from the laboratory, they
could be dangerous.

Berg was persuaded by this argument
and decided not to do the experiment.
He led molecular biologists in calling for
a moratorium on recombinant DNA re
search until the risks could be assessed
.ind the safety of the experiments en
sured. It was a period. Berg recalls, "of
more controversy than science." In
19?5. the moratorium w-as conditionally
lifted and the National Institutes of
Health developed guidelines for the con
duct of recombinant DNA experiments.
The guidelines have since been softened
as the experiments turned out to be less
risky than anticipated.

Ironically, the experiment that Berg
originally wanted to do would not have
succeeded, and no one at the time would
have known uny. The SV40-A hybrid
would not have replicated in bacteria be
cause Berg inserted the SV40 genes at a
site now- known to be essential for \'s
replication and thereby interrupted this
site.

In fact, the heart of recombinant DNA_
technology is not just gene splicing but
also gene cloning. It is necessary to find
ways to get foreign genes into cells, en
sure that the genes are expressed, and
then select for the cells that are ex
pressing those genes. Cloning techniques
were pioneered by Stanley Cohen and
Annie Chang of Stanford University and

242

Herbert Boyer and Robert Helling of the
University of California at San Fran
cisco, who, in the early )970's, devel
oped a plasmid. which is a small piece of
extra-chromosomal DNA, that could
carry foreign genes into bacterial cells.
The plasmid contained genes that made
the bacteria resistant to the antibiotic tet-
racycline, so that the cells which took up
the plasmid and expressed its genes
could easily be selected.

In the past decade, recombinant DNA
techniques have become increasingly so
phisticated. Berg has played a major role
in these developments. Most recently,
he and others, particularly Daniel Na
thans of Johns Hopkins University Med
ical School, who won a Nobel Prize for
his work in restriction enzymes, exten
sively studied the structure, organiza
tion, and replication of SV40 genes. Af
ter constnicting deletion mutants of
SV40 that have proved extremely useful
in studies of SV40 gene functions. Berg
went back to his original idea of using
SV40 to introduce genes into mammalian
cells. He spliced to SV40 an E. coli gene
that allows cells tc use xanthine as a sub
strate in nucleotide synthesis. Then, in
separate experiments, he spliced animal
genes for globin. histone. or the enzyme
dihydrofolate reductase to this hybrid
SV'40 molecule. When the SV40 carrying
the added bacterial and animal genes was
introduced into cultured cells. Berg
could pick out the cells that were trans
formed by SV40 by selecting for cells
that grow- on xanthine. In this way. Berg
was able to show that the added animal
gciu-3 ai'c c.xpiesscJ in cultured cells.

Dean Hamer and Philip Leder of the
National Institute of Child Health and
Human Development have also used
SV40 as a cloning vector in cultured
cells. But. says Nathans. "Clearly the
notion that you could construct a vector
with animal viruses was Berg's idea."

An important aspect of .Berg's work
has been his extraordinary ability to de
velop methodologies. For example, he
was the first to use nitrocellulose binding
assays to study interactions between
proteins and nucleic acids. He also de
veloped the nick translation method,
which is used to make isotopically la
beled DNA probes and is central to cur
rent studies of gene functions. "His style
of biochemistry helped set the standards
in the nucleic acid field." says Nathans.

The second half of the chemistry prize
was also given to developers of method
ologies. Sanger and Gilbert were hon
ored for their discoveries of ways to se
quence DNA. In the past few years,
these techniques have become widely
used to determine amino acid sequences

of proteins because with these method
it is/easier and more accurate to se
quence the DNA coding for proteins
than to sequence the proteins directly.
The techniques are also used to deter
mine the intervening sequences that oc
cur in eukaryotic genes and the se
quences that occur in control regions of
bacterial DNA. By using these methodv
molecular biologists hope to learn whi.'i
sequences control gene expression .1
higher organisms and how they do so
"DNA sequences are the basic, under
lying structures [of molecular biology].
There is nothing more primitive. Your
questions are ultimately posed there,"
says Gilbert.

Sanger and Gilbert are about as dif
ferent as two scientists can be. and they
came upon their sequencing methods by
entirely different paths. Sanger is qu :.
modest, self-effacing; Gilbert is much
more flamboyant. Ted Friedman of the
University of California at San Diego,
who spent a sabbatical year with Sanger.
says. "If you talk to Sanger and do not
know who he is. you would think he is
the lab caretaker. If you allow him to. he
will melt into the woodwork." George
Brownlee of Oxford University, who un
til recently was at Cambridge with S..: :-
er. adds, "Sanger certainly doesn't give
himself airs. But in my view, he ranks
among the great scientists of our time."

According to Friedman. Sanger's out
standing feature is his "uncanny belief
and knowledge that sequencing can be
determined by very simple methods." In
the 1950's, Sanger studied protein se
quencing -it .1 tirr; when no one l--y.v
whether all proteins of a particular :; pe

Walter Gilbert

'have the same sequences. His first Nobel
i Prize was awarded for this work. Then
\ ),e attacked the problem of RNA se-
I quencing. developing the widely used
.' fingerprinting method. About 10 years
\ ago. he set out to sequence DNA. even
*-. thoir-h this problem, too. was consid
ered intractable.

S.inger's method evolved gradually
from more than one line of attack on the
problem. In the early 1970's. he discov
ered the plus-minus sequencing method,
a direct precursor of the method he uses
today. In the plus-minus method the ob
ject is to obtain a set of nested segments
of the DNA to be sequenced. The first
segment consists of the first nucleotide,
. the second consists of the first two nucle
otides. the third of the first three nucle-
otides. and so on. These segments are
constructed in such a way that the identi
ty of the last nucleotide of each nested
segment is known. Once obtained, the
nested segments can be separated ac
cording to size by electrophoresis on an
ultrathin polyacrvlamide gel. The sepa
rated fragments can be delected because
e:'.:h is isotopically labeled.

ir.c ke> l\j llic pli.i-nuni;^ method U
obtaining the nested segments. Sanger
constructs them by synthesizing them.
He separates the two strands of the DNA
to be sequenced and then makes partial
copies of one of those strands. To ensure
that the partial copies include all nested
segments and that the terminal nucle
otide of each segment is know-n. Sanger
m ikes the copies under conditions in
which one nucleotide is limited in quanti
ty For example, he provides limited
quantities of adenine so that the DNA
copying will eventually stop because of
lack of adenine. Then all of the copies
made will end just before an adenine.
and the next nucleotide of each of the re
sulting segments is adenine. In a similar
way. Sanger synthesizes segments end-
is'.;: before each of the other three DNA
nucleotides.

Sanger has since improved the plus-
minus method to make it more efficient.
Instead of supplying limited quantities of
each nucleotide. he supplies derivatives
of the nucleotides that cause DNA syn
thesis to stop.

In contrast to Sanger. Gilbert did not
deliberately set out to sequence DNA. A
highly visible, active scientist who runs a
i;irge laboratory. Gilbert has worked on a
"•ide variety of problems in the past 20
years, ranging from how bacterial genes
are organized and expressed to gene con
trol in higher organisms and genetic engi
neering. He is also chairman of the board
and cochairman of the board of directors
of the gene splicing firm Biogen.

:i NOVEMBER 1980

Gilbert, working with Allajn Maxam.
who is now at Harvard MedicaJ School's
Sidney Farber Cancer Institute, came
upon a DNA sequencing technique aJ-
most by chance. Gilbert recalls that one
day in early 1975. Andrei Mirzabekov, of
the USSR Academy of Sciences, ap
peared in his office and urged him to try a
new approach to studying how proteins
recognize specific sequences of DNA.
Gilbert had long been interested in the
lac represser protein of £. coli. which
binds to the lac operon segment of DNA.
and. in fact, it was Gilbert who isolated
the lac represser and operator. Mirzabe
kov and his colleagues had been probing
protein-DNA interactions with dimethyl
sulfate. a reagent that methylates the
DNA nucleotides adenine and guanine.
After reacting with dimethyl sulfate.
DNA breaks easily at these bases.

Gilbert decided to expose lac operon
DNA to dimethvl sulfate and then break

. c

« 1

•

«•
T

^ • •

< -•

C. ****

Purl of the sequencing pattern obtained from
a piece of Di\A about 130 base pairs in
length. The letters at the top of the columns,
A. C, C, and T (adenine, guanine, cyto-
sine, and thymine) indicate which base'*as
preferentially cleaved by chemicals. Tue dark
est band in each column represents the base
missing from the end of the initial segments,
with the exception of cytosine (C). All dark
bands in the C column represent cytosines
e\en if bands also appear in the T column at
that position. Bands that appear in the T
column but not in the C column represent thy-
mines IT>. To read the sequence of the DNA .
read off the base represented by each bund,
sinning from the bottom of the columns.
[Source: Wiiller Gilbert and Allan Mu.ram]

the DNA at adenines and guanines. For
comparison, he would bind lac represser
to the operon and repeat the experiment.
The adenines and guanines that reacted
with the represser should be protected
from the dimethyl sulfate, and so the
DNA should not break there. Since the
sequence of lac operon DNA was known
(it had been copied into RNA and the
RNA sequenced). it would be possible to
learn where the represser binds on this
DNA.

After these experiments. Gilbert and
several of his associates discovered a
second lac operon of unknown se
quence. Maxam repeated the dimethyl
sulfate experiments with this new lac op
eron and the lac represser. When he and
Gilbert saw the results, they realized that
they had the beginning of a DNA se
quencing method. By using dimethyl sul
fate and adjusting the reaction condi
tions, they could break DNA at either
adenines or guanines. Now if they could
find a way to break DNA preferentially
at thymines or cytosines, they could gen
erate nested segments whose terminal
nucleotides were known. With this idea.
Maxam set to work to develop ways of
breaking DNA at tli>mini.-b c: c>iu>ine>.
He recalled that under appropriate chem
ical conditions, hydrazine preferentially
weakens DNA at one or the other of
these nucleotides. After a summer of
work. Maxam succeeded in perfecting
the chemical method of sequencing
DNA.

The difference between the Sanger
method and the Maxam-Gilbert method
is that Sanger generates nested segments
by synthesizing them and Maxam and
Gilbert generate the segments by break
ing the DNA at specific bases. Both
methods are currently used, and re
searchers experienced with both say that
the choice between them depends in part
on the length of DNA to to be sequenced
and in part on the personal preferences
of the investigator. Tom Maniatis of the
California Institute of Technology, for
example, uses Sanger's method for very
long sequences of DNA because it is
faster. For shorter sequences, one or a
fey genes long, the two methods are
comparable in speed, but Maniatis pre
fers the Maxam-Gilbert method because
"Allan has established the protocol so
completely that anyone who tries the
method is successful."

The full ramifications of recombinant
DNA technology and DNA sequencing
methods are not yet known. But these
techniques are changing molecular biolo
gists' perceptions of what can be learned
about the genes of higher organisms.

_GINA BARI KOLATA

889

INDEX--Paul Berg

244

Abraham Lincoln High School, 4-7
Albert Einstein College of

Medicine, 172
ALZA [Corporation], 138, 149,

152, 157, 161-162
American Cancer Society, 32, 33

Scholar in Cancer Research, 39
Amgen, 142
amino acid assembly/activation,

43-45. See also protein

synthesis /assembly
antibiotic resistance, 77
anti-Semitism, 8, 15
Arai, Kenichi, 152, 163-165
Arrowsmith, 3

artificial kidney research, 17
Asilomar, 136, 185
Asilomar 1 [Conference on

Biohazards in Biological

Research], 70, 72-73, 75-76,

92-94, 115, 120, 161, 185
Asilomar II [Conference on

Recombinant DNA] , 72, 74, 76,

77-79, 121

bacteriophage, 32, 54, 60-61, 88,

as transducing agents, 64-65

complimentary tails, 66-67, 89

lambda, 52-53, 64-66, 68-69,
82, 88, 90, 103, 108

pi, 84-85

p22, 108, 111

phiSO, 65, 82, 88

T-4, 60

X, 59

Baldwin, Robert "Buzz", 175
Baltimore, David, 71, 74, 120,

138, 147

Beadle, George, 61
Beckman Center for Molecular and

Genetic Medicine. See Stanford

University

Beckman Foundation, 178
Beckman, Arnold, 181-183
Benzer, Seymour, 51
Berg, Irving, 5
Berg, Jack, 5
Berg, Millie, 13
Biochemical and Biophysical

Research Communications, 129-

130
Biochemistry Department, Stanford,

90. See also Stanford

University
Biogen, 159-160
biohazards/biosafety , 71-80

NIH, 74

Salk Institute, 72-73

Watson stance, 76

See also Asilomar I and II
Bishop, Mike, 57, 176, 179
Bodmer, Walter, 173-174
Bohr, Niels, 28-29
Bollum, Fred, 89, 128
Boyer, Herbert, 70-71, 77-78, 95,

99, 101-102, 105, 112-113, 117-

118, 120-122, 126, 139-141
Brenner, Sydney, 156
Brodsky, Sarah (mother), 1
Broker, Tom, 125
Bronx High School of Science, 6
Brooklyn College, 9-10
Brooklyn Tech, 9
Brown, Don, 87, 114
Brown, Mike, 179

Calgene, 144
Caltech, 177
Cambridge Medical Research

Council, 57, 63
Cantor, Harvey, 163
Cape, Ronald, 141
Carnegie Labs, Johns Hopkins, 87,

114
Cavalli-Sforza, Luca, 174

245

Cetus [Corporation], 117, 141-

142, 144-145
Chamberlain, Mike, 45
Chemical and Engineering News, 25
Ciba-Geigy, 157
City College of New York, 8
cloning (DNA) . See recombinant

DNA method
Cohen, Stanley, 110, 126, 172-174

recombinant DNA method, 69-71,
77-78, 101, 105-106, 112-122

relation to Stanford

biochemistry dept., 90, 95,
116-119, 142, 144, 181, 183
Cohn, Melvin, 51-52
Cold Spring Harbor Laboratory,

76, 88, 91, 98, 125
Congressional training grants,

134-135
consulting in academia, 138, 143-

148
Cori, Carl, 25-27, 30, 34, 40, 58

Nobel Prize with wife, Gerty,

27, 124

Cornell Medical School, 19
Crabtree, Jerry, 183
Crick, Francis, 33, 44, 46, 48,

Cuzin, Francois, 59, 99
cytokines, 163-164, 166-168

d'Andrade, Hugh, 160

Danish Royal Academy of Sciences,

28-29
Danish State Serum Institute

(Copenhagen) , 32
Davis, Ronald, 71, 100-102, 120-

122

de Kruif, Paul, 3
Dieckmann, Marianne, 59
Djerassi, Carl, 132-133, 142
DNA

replication, 46-51, 54, 60-61,
66, 71, 89, 90, 112

structure, 33

synthesis, 46-48, 68, 95, 96

transcription/translation, 45,
51, 60, 84-85

DNAX Research Institute, 138-139,
149-169. See also Schering
Plough

Drosophila genetics, 59, 61, 63,
70, 112

du Pont, 133

du Vigneaud, Vincent, 19, 22

Dulbecco, Renato, 59

Dynapol, 162

enzyme /enzymology, 21, 62-63
activation, 51-52
enzyme reactions, 26, 29, 30,

36-37, 42, 89
Kalckar, 41

Kornberg, 21, 25, 40-41
ligase, 67-68, 96-97, 108,

130, 175

nucleic acid, 21, 35
purification, 25, 36-37, 41-

42, 44-45, 47-48, 57, 61,

63, 87
terminal transf erase, 111,

128-129

fatty acid activation, 38, 42
Federation for Experimental

Biology meetings, 38
Fredrickson, Don, 180-182
Friedman, Ted, 92

G.I. Bill, 19
Ganeson, 174
Gellert, Martin, 67
gene

expression, 51-52, 54-55, 58,
60, 66, 71, 84-85, 104, 155,
164

regulation, 51-53, 55, 58, 85,
155

repression, 52-54

selection, 83

therapy, 74-75, 104

transfer, 82, 84, 86
Genentech Inc., 117, 139-141
General Foods Corporation, 13

246

genetic engineering, 75, 81, 123,

136, 138, 154, 162
Genetics Institute, 164, 166
germ warfare, 91, 94
Gilbert, Wallace, 126
Glaser, Don, 141-143
Goldstein, Joe, 179
Gordon conference, 119-120
Goulian, Mehran, 131
graduate student teaching, 18-19

Haber, Edward, 152-156
Hall, Eliza Institute, 173
Harvard, 43, 45, 99, 107, 151-

152, 163

Hayaishi, Osamu, 34
Helling, Robert, 115-116
Hershey, Alfred, 67, 88
Hertzenberg, Leonard, 173
Hoagland, Mahlon, 43-45
Hogness, David, 51-52, 59, 70-71,

112, 120-122
Hood, Lee 153, 164
hoof and mouth disease, 77
Hughes, Howard, 183

Medical Institute at Stanford,

180-184
Hurwitz, Jerry, 112-113, 172

ICRF, 57

Immunex, 166

immunology, 152, 157, 160-163,

165-168, 174, 178
Industrial Affiliates Program

[IAP], Stanford, 132-137
Institute for Research on Aging,

Stanford, 134

Jackson, David, 69, 72, 92-95,
97, 102-103, 107, 109, 111, 131

Jacob, Francois, 52, 55, 58-59

Jensen, R.H., 110-111, 123, 129-
131

Joklik, William, 29

Kaiser, Dale, 51-53, 56, 59, 66,

68, 88, 103, 107, 114, 133,

137, 174

Kalckar, Herman, 24-33, 41
Kaplan, Henry, 146
Kennedy Foundation, 175
Kennedy, Donald, 144, 182
Kenyon, Cynthia, 63
Kern, Dave, 182
Khorana, Gobind, 57, 96-98, 127,

175

Kolff , Willem J. , 17
Koprowski, Hilary, 110
Kornberg, Arthur, 5

academic background, 40-41

ALZA/DNAX, 149-169

apprenticeship with Cori, 27

City College, 7

consulting fees, 146

DNA polymerase I, 89, 96, 128,
131

DNA replication, 46-51

DNAX, 139

E. coli in research, 56-58

enzyme access at Stanford, 67

enzymology, 21, 25

high school, 6-7, 25

meeting Berg, 24

nearest neighbor experiment,
48

NIH, 27-28, 34, 40-41

Nobel Prize, 6, 123, 125-127
Committee, 125, 126

Paul-Lewis Award, 25, 41

professor of microbiology at
Washington Univ., 27-28,
33-36, 38-39, 46

Senate testimony, 75

Stanford biochemistry IAP, 133

Stanford departments, 174,

182, 185

Kornberg, Roger, 57
Kornberg, Tom, 63
Kornberg, Sylvy, 34

Lear, John, 102

Lederberg, Joshua, 75, 81, 91-92,
141-142, 171-174

247

Lehman, Bob, 67, 89, 137
Lennette, Edwin, 78
Leonard, Jack, 17
Levy, Mildred, 4
Lewis, Andy, 75, 78
Lewis, Sinclair, 3
Lhu, Gilbert, 176
Lieberman, Irving, 34
Lipmann, Fritz, 35-36, 38
Lipton Tea Company, 13
Lobban, Peter, 68-69, 102-111,

122, 128, 131
Lowry, Oliver, 34
Luciano, Robert P., 159, 167
Luria, Salvador, 32, 33
Lwoff, Andre, 52-53, 58
Lyman, Richard W. , 143
Lynen, Feodor, 35-36, 38
lysogeny, 53-54, 80-86, 88

Maaloe, Ole, 32

Mack, [Senator] Connie, 57

mammalian cell biology, 60, 65-

66, 69, 74, 77, 83-87, 90, 104-

105, 107, 118, 119
Mandel, Mort , 114, 173-174
Maniatis, Tom, 154
Markey Fellowship, 39
Massachusetts Institute of

Technology [MIT], 70, 98, 147,

149, 177

biohazards meeting, 74, 76,

120-121, 161
Matsubara, Kenichi, 66
McDevitt, Hugh, 142, 144, 181
Melman, Kenneth, 179, 181, 183
Merck, 111-112
Mertz, Janet, 91, 98-102, 114,

116, 173-174
Meselson, Matthew, 99
messenger RNA, 44-45, 49-51, 60,

84-85

Meyers, Victor, 16, 17
Microbe Hunters, 3
monoclonal antibodies, 153-156
Monod, Jacques, 52, 55, 58
Moore, Kevin, 153, 164

Morrow, John, 99-102, 105-106,

112, 114-116, 119-120, 128
Mullis, Gary 127
mutations, 60-64, 74, 104, 127

Nathans, Daniel, 71
National Academy of Sciences,

119-121
National Institutes of Health

[NIH], 27, 28, 32, 40, 57, 75,

180
New York City

Brighton Beach, 2

Brooklyn, 2, 25

Coney Island, 2
Nobel Prize

Berg, 6, 69

acceptance speech, 117,
122-127

Jerome Karle, 6

Gobind Khorana, 57

Arthur Kornberg, 6

Fritz Lipmann, 35

Vincent du Vigneaud, 19
Nobel, Alfred, 127
Nossal, Gustav J.V., 174
nucleic acid biology/biochemistry,

29-30, 35-38, 46, 50, 57, 85,

89, 96
nutrition research, 12, 19-21, 42

nutritional supplement
research, 19-20

Oak Ridge National Laboratory,

22, 23
Ochoa, Severe, 40, 57, 123, 185-

186

Ofengand, James, 43
Okayama, 154-155, 164-165
Oklahoma A and M (Oklahoma State

University), 15-16
Omura, 156
oncogenesis, 54, 57, 73, 77

Pasteur Institute, 51-52, 59
patenting, 115-116

248

Paul-Lewis Award in Enzyme

Chemistry (Berg), 41
Pennsylvania State University,

10-14

plasmidology, 95, 112, 115
Plum Island, 77
polio vaccine, 56, 93
Pollack, Bob, 91-92
polymerase chain reaction [PCR] ,

127
postdoctoral positions (Berg)

Copenhagen, 26

St. Louis (Washington

University), 26-28
protein synthesis, assembly, 42-

45, 49-51, 51-52, 64
Public Health Research Institute

in New York, 25
Purpura, Dominick, 181

radioisotopes , 14-15, 18, 22-24,

46-47
recombinant DNA

biohazards controversy, 56,
71-81, 91-94, 119-122, 125-
126, 139, 179
"Berg" moratorium letter,

71, 74, 76, 120-122, 161
James Watson, 76, 120-121
commercialization of

biomolecular science, 116-
117, 132-153

commercial reagents, 60
See also DNAX

method, 69-71, 77-78,
101, 105-106, 112-122
regulatory policy, 81
restriction enzymes, 70, 94-
95, 99, 113
EcoRl, 99-102, 112-114,

116, 119, 128-129, 173
science, 64-90, 92-118, 121-
131, 136-137, 140-142, 152,
162

cohesive ends, 66-67, 88-
90, 94-95, 98-103, 108,
111, 113, 129, 173
See also Asilomar II

ribosoraes, 44, 87
Roberts, Richard, 125
Robertson, Channing, 150-152
Roblin, Richard, 71, 74
Rogoff, M.H., 110
Roosevelt, President Franklin

Delano, 7

Rosenberg, Thomas, 29-30
ROTC [Reserve Officer Training

Corps], 9

Rothchild [Venture Capital], 156
Rutter, William J., 140-141

Sakami, Warwick, 20

Salk Institute, 59, 65, 84-85

Salk, Jonas, 56

Sanger, Eugene, 126

Schering-Plough, 157-163, 167-

168. See also DNAX
Schodnick, Gary, 183
Science for the People, 80
Sgaramella, Vittorio, 96-98, 102,

108, 122, 172, 175
Sharp, Phil, 125
Shooter, Eric, 175-176

Shooter Committee on Conflicts
of Interest, Stanford, 145-
148

Silicon Valley, 134
Singer, Maxine, 61, 120, 161
Skaggs, Leonard, 17
smallpox, laboratory outbreak, 80
Smith, Michael, 127
SmithKline Beecham, 182
space biology, 173-174
Spudich, Jim, 177
Stanford University, 52, 58-59,

66-67, 72-73, 88-89, 94, 96-98,

112, 129, 132-137, 140, 142,

144, 167-187

Beckman Center for Molecular
and Genetic Medicine, 62,
110, 177-185

Berg achievements, 185-187

biochemistry dept., 172-176

genetics dept., 171-175

Howard Hughes Medical
Institute, 180-184

249

Stanford University (cont'd.)

Industrial Affiliates Programs,
132-137

Program in Molecular and

Genetic Medicine, 184
Stark, George, 57
SV40 [Simian Virus 40], 54-56,

59, 64-65, 69, 71-72, 75-77,

85-87, 89-90, 92-93, 95, 97-

100, 104, 107-109, 119

genome, 60, 65-66, 68, 76, 117
Swanson, Robert, 140
Swedish Royal Academy, 122, 127
Symons, Robert H. , 69, 93, 102,

109, 129, 131
Syntex, 142, 158

Takeda Chemical, 156
Tokyo University, 165
transduction

transduction system, 65-66,

80-86, 102, 104, 119
agents, 64-65
transfer RNA (tRNA), 43-45, 49-

51, 64
tumor virus research

mammalian, 53-61, 65, 72, 75-

77, 84-85, 91-94, 120, 164
polyoma, 54-56, 65, 84-85
SV40 [Simian Virus 40], 54-56,
59, 64-65, 69, 71-72, 75-77,
85-87, 89-90, 92-93, 95, 97-
100, 104, 107-109, 119
genome, 60, 65-66, 68, 76,

117

Ultimate Experiment, 71
University of California, 144
UC Berkeley, 45
UC Davis, 144
UCSF, 63, 99, 117, 139-141,
176-178
Program in Biological

Sciences, 176, 178
University of Michigan, 72, 92

Vietnam War, 80

Wade, Nicholas, 71, 94

Waitz, J. Allan, 159-160

Wang, Jim, 107

Washington University (St. Louis),

26-28, 33-34, 39, 51-52, 170
Watson, James D. , 32-33, 44, 46,

48, 71, 74

biohazard position, 76, 120-

121

Weiner, Charlie, 149
Weissman, Irving, 183
Weissman, Sherman, 71
Western Reserve Medical Center,

19
Western Reserve University, 14-24

Department of Biochemistry,
17-26

Department of Clinical

Biochemistry, 16-17, 20
Wodzinski, R.J., 110
Wolf, Sophie, 5-7
Wood, Bill, 45

Wood, Harland, 15-16, 18, 20-27
World War II, 7
- Hiroshima, 12

occupation and rationing in
Denmark, 31

Pearl Harbor, 7

radiation labs, 22-23

service, 11-12
Wright, Barbara, 32
Wright, Susan, 81

Yanofsky, Charles, 64, 69, 82,
102, 107, 139, 149-153

Zaffaroni, Alejandro, 138, 142,

150-158

Zamecnik, Paul, 43-45
Zinder, Norton, 71, 74, 81
Zurowski, Gerard, 153, 64-165

Valentine, Ray, 144
Varraus, Harold, 179

Sally Smith Hughes

Graduated from the University of California, Berkeley, in
1963 with an A.B. degree in zoology, and from the University
of California, San Francisco, in 1966 with an M.A. degree in
anatomy. She received a Ph.D. degree in the history of
science and medicine from the Royal Postgraduate Medical
School, University of London, in 1972.

Postgraduate Research Histologist, the Cardiovascular
Research Institute, University of California, San Francisco,
1966-1969; science historian for the History of Science and
Technology Program, The Bancroft Library, 1978-1980.

Presently Research Historian and Principal Editor on medical
and scientific topics for the Regional Oral History Office,
University of California, Berkeley. Author of The Virus: A
History of the Concept, Sally Smith Hughes is currently
interviewing and writing in the fields of AIDS and molecular
biology /biotechnology .

2495

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Full text of "A Stanford professor's career in biochemistry, science politics, and the biotechnology industry : oral history transcript / 2000"

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