TEXAS TECH UNIVERSITY Natural Science Research Laboratory Occasional Papers Museum of Texas Tech University Number 256 27 July 2006 Intron 2 of the Alcohol Dehydrogenase Gene (Adh1-\2): A Nuclear DNA Marker for Mammalian Systematics Brian R. Amman, J. Delton Hanson, Lisa K. Longhofer, Steven R. Hoofer, and Robert D. Bradley Abstract DNA sequences from a novel nuclear marker (2nd intron of the vertebrate alcohol dehydro¬ genase gene, Adh\-\2) and the mitochondrial cytochrome-/) gene ( Cyt-b ) were examined in 41 species and six genera of rodents (one Holochilus , 13 Neoloma , six Oryzomys , one Ototylomys, 19 Peromyscus , and one Tylomys). The Adh 1 -12 dataset was characterized by having a significant level of phylogenetic signal (P< 0.01) and a low level of homoplasy (consistency index = 0.78, retention index = 0.89), Based on parsimony, maximum likelihood, and Bayesian analyses, the Adh\-\2 results were congruent with results from Cyt-b and other types of data, and generally were accompanied by high statistical support. All phylogenetic relationships at and above the genus level were strongly supported. Furthermore, compared with Cyt-b, the Adh 1-12 dataset provided supported resolution to more species-level relationships within Neotoma, Peromyscus , and Oryzomys , despite fewer overall characters (489 Adh 1 -12; 1,143 Cyt-b ) and fewer parsimony informative characters (126 Adh 1-12; 464 Cyt-b). Overall, results of this study indicated that Adh\-\2 DNA sequences are useful for addressing phylogenetic relationships within and among the Sigmodontinae andNeotominae. The slower rate of molecular evolution observed in Adh\- 12 sequences, coupled with low levels of homoplasy and strength of resolution for supraspecific relationships, indicated that this marker may be useful for resolving phylogenetic relationships at low to intermediate taxonomic levels in mammals. Key words: alcohol dehydrogenase gene, cytochrome-/) gene, molecular systematics, rodents 2 Occasional Papers, Museum of Texas Tech University Introduction The use of nucleotide sequence data has greatly enhanced our knowledge of mammalian systematics. In mammals, the majority of molecular-based phylogenies have been estimated by analysis of maternally inherited, mitochondrial DNA (mtDNA) sequences, especially protein coding genes. Advantages in using mtDNA sequences in phylogeny reconstruction include: tech¬ nical ease in DNA isolation and polymerase chain reaction amplification, manageable sequence lengths (generally <1,200 base pairs, bp), ease of alignment, availability of “universal” primers, differential rates of molecular evolution in specific regions of the molecule, significant phylogenetic signal, and substantial data¬ bases (GenBank, EMBL, etc.) of comparative material. However, there are drawbacks to mtDNA that can result in a misrepresentation of the true phylogeny, includ¬ ing retention of ancestral polymorphisms, incomplete lineage sorting, differential rates of evolution among lineages, and hybridization (Avise 1994; Hillis et al. 1996; Prychitko and Moore 2000). Likewise, base composition of mtDNA protein coding genes (excess of C and A at the 3rd positions - Anderson et al. 1981; Roe etal. 1985; Desjardins and Morais 1990; Prychitko and Moore 2000; Ballard et al. 2002) may result in codon bias and homoplasy (Prychitko and Moore 2000) lead¬ ing to a biased reconstruction of ancestral sequences (Collins et al. 1994; Lockhart et al. 1994; Perna and Kocher 1995). Although some of these drawbacks can be addressed, nuclear DNA sequences are highly desirable as an alternative dataset to independently test mtDNA hypotheses and to essentially counteract criticisms of mtDNA. Historically, nuclear DNA sequences have been used to address phylogenetic questions pertaining to relationships above the genus level (e.g., rRNA genes - Gouy and Li 1989; Perasso et al. 1989), principally because nuclear sequence markers with levels of varia¬ tion suitable for resolving relationships among closely related species or genera are scarcely known and have been difficult to discover. Intron markers are an obvi¬ ous and likely source of nuclear variability suitable for low- or intermediate-level phylogenetics. With the exception of some conserved areas, such as regulatory sites (Jackson and Hoffmann 1994), most nucleotide positions within introns are adaptively neutral and independently distributed and generally are evolv¬ ing faster than those within exons, thus increasing their potential in population genetics or phylogenetic analysis of closely related species (Ballard et al. 2002; Prychitko and Moore 2000; Slade et al. 1994; Wick- liffe et al. 2003). In addition, introns of various sizes are relatively abundant in the nuclear genome, and usually primer design in conserved areas of adjacent exons enable efficient amplification across taxonomic boundaries. In vertebrates, several introns have been shown to be useful in studies at or below the genus level (Prychitko and Moore 1997, 2000; Oakley and Phillips 1999; Lavoue et al. 2003; Reeder and Bradley 2003; Johansson and Ericson 2004; Helbig et al. 2005), and others have been shown to be relatively invariant at or below the species level (Wickliffe et al. 2003; Carroll and Bradley 2005). Alternatively, Fonseca et al. (in press) and Porter et al. (in review) found intron sequences useful for resolving relationships among closely related species of bats. The purpose of this study was to examine the phylogenetic utility of DNA sequence data from the 2nd intron of the alcohol dehydrogenase gene 1 (Adh 1) obtained for 41 species in six genera of rodents. Adh genes, in mammalian systems, code for dimeric zinc- metallo enzymes that catalyze oxidization of alcohols to aldehydes or ketones (Szalai et al. 2002). Seven distinct classes are recognized in vertebrates (Duester et al. 1999; Dolney et al. 2001; Szalai et al. 2002), six of which are present in mammalian species (Duester et al. 1999; Szalai et al. 2002). In rodents, four Adh classes (I, 11, III, and IV) have been reported (Crabb and Edenberg 1986; Zhang et al. 1987; Park and Plapp 1991; Bradley et al. 1993, 1998; Duester et al. 1999; Szalai et al. 2002) and are controlled by six genes, Adh \, Adh2, Adh3, Adh4, AdhSa, andH<7/?5b (Duester et al. 1999; Dolney et al. 2001; Szalai et al. 2002). Adh 1 is approximately 13 kilobase pairs in length (Crabb et al. 1989), contains nine exons (coding between 6 and 87 amino acids) and eight introns (ranging from 91 bp to 3.6 kilobase pairs; Zhang et al. 1987). Hereafter, in referring to the 2nd intron, we follow the recommended nomenclature (Adh [-12J of vertebrate alcohol dehydro¬ genases outlined in Duester et al. (1999). Amman et al.-Alcohol Dehydrogenase and Mammalian Systematics 3 Materials and Methods Specimens examined.- —Specimens examined, GenBank accession numbers, and information associ¬ ated with museum vouchers are listed in Appendix I. Complete sequences for Adh\-\2 and cytochrome-/) ( Cyt-b) were obtained for 41 individuals and 10 indi¬ viduals, respectively, and were deposited in GenBank. In addition, 31 Cyt-b sequences were retrieved from GenBank. Holochilus chacarius was designated as the outgroup taxon in phylogenetic analyses of Adh\-\2 and Cyt-b data, as previous morphological and mo¬ lecular studies agree that Holochilus may be outside the remainder of taxa in this study (reviewed in Musser and Carleton 2005). Sequence data were evaluated and relationships were inferred among the 40 ingroup species (13 Neotoma, six Oryzomys , one Ototylomys, 19 Peromyscus, and one Tylomys) representing the subfamilies Neotominae and Sigmodontinae (Musser and Carleton 2005). Adh7-/2 data. —Genomic DNA was isolated from approximately 0.1 g frozen muscle or liver tissues by the method of Smith and Patton (1999). Polymerase chain reaction (PCR; Saiki et al. 1988) primers for Adh 1-12 (Table 1) were designed from conserved regions in exons 2 and 3 based on sequences from Homo (Ikuta et al. 1986), Geomys (Bradley et al. 1993, 1998), Mus (Zhang et al. 1987), Peromyscus (Zheng et al. 1993), and Rattus (Crabb et al. 1989). A nuclear fragment approximately 650 bp long, encompassing the entire Adh\-12, was amplified in all six generalising two for¬ ward primers (2340-1 or EXON 1I-F) and two reverse primers (2340-11 or EXON III-R). PCR thermal profiles varied only slightly among genera examined: initial denaturation at 95°C for 2-10 min, followed by 25-30 cycles of denaturation at 95°C for 30-60 sec, annealing ramped from 52-53°C down to 46-48°C and back up to 52-53°C at a rate of 0.6°C/sec, extension at 73°C for 1.5 min, and a final extension cycle of 73°C for 4 min. Ramping speed between all three phases of PCR was set at a rate of 1 °C/sec. Reaction concentrations (35 pi volume) included approximately 300 ng genomic DNA, 0.07 mM dNTPs, 2.86 mM MgCl, 3.5 pi 10X buffer, 0.286 pM primer, and 1.25-1.5 U enzyme (FailSafe PCR Enzyme Mix, Epicentre, Valencia, California). In some reactions, 1.5 U AmpliTaq Gold (PE Applied Biosystems, Foster City, California) was used with an initial denaturation time of 10 min. PCR products were purified using the QIAquick PCR purification kit (Qiagen, Valencia, California) and sequenced with Big-Dye version 3.1 chain terminators (Applied Biosystems, Inc., Foster City, California). Appropriate external primers and four internal prim¬ ers (350F, 350R, 41 OF, 41 OR; Table 1) were used to sequence each strand entirely. Thermal profile for cycle sequencing was modified from the manufacturer’s recommendation: 25-30 cycles of 95°C for 30 sec dena¬ turation, 50°C for 20 sec annealing, and 60°C for 3 min extension. Sequencing reactions were precipitated and concentrated with standard isopropanol methods, re¬ suspended in 15ml Hi-Di Formamide, and electropho- resed on an ABI31 00-Avant Genetic Analyzer (Applied Biosystems, Inc., Foster City, California). Sequencher 3.0 software (Gene Codes, Ann Arbor, Michigan) was Table 1. Primer sequences used in the polymerase chain reaction (PCR) amplification and sequencing of the alcohol dehydrogenase locus. Sequences are given in a 5'to 3 ’orientation. Primer Sequence 2340-1 (5’PCR primer) 2340-11 (3’PCR primer) EXON II-F(5’ PCR primer) EXON III-R (3’PCR primer) 350F (internal sequencing primer) 350R (internal sequencing primer) 41 OF (internal sequencing primer) 41 OR (internal sequencing primer) GTAATCAAGTGCAAAGCAGCTG TAACCACGTGGTCATCTGAGC'G GTAATCAAGTGCAAAGCRGCYYTRTGGGAG GACTTTATCACCTGGTTTYACWSAAGTCACCCC GTGCTAAACATCTTGATTCCRAAAG GCTTTTGGAATCAAGATGTTTAG CTATAGCACAGCACAGC TGCTGTGCTGTGCTATAG 4 Occasional Papers, Museum of Texas Tech University used to assemble and proof resultant fragments. Base calling ambiguities on single strands were resolved by choosing the call on the cleanest strand or by us¬ ing appropriate IUB ambiguity code if both strands showed the same ambiguity. Because provisional statements of homology (i.e., sequence alignment) are of special concern for non-coding DNA sequences possibly containing in¬ sertion/deletions (Giribet and Wheeler 1999), and be¬ cause many parameters can affect multiple-sequence alignment and resulting phylogenetic inference (De- Salle et al. 1994; Hickson et al 2000; Lutzoni et al. 2000; Wheeler 1995), two multiple-sequence align¬ ments ofzk//?l -I2 data were performed independently in Clustal X software (Thompson et al. 1997): one using a 30:4 gap cost-ratio, the other using a 5:4 gap cost-ratio (Van Den Bussche and Hoofer 2001; Van Den Bussche et al. 2002). Alignments subsequently were examined using MacClade software (version 4.05; Maddison and Maddison 2002), ambiguously aligned sites were delimited following methods of Hoofer and Van Den Bussche (2003), and analyses were performed with and without those sites. Cyt-b data .—Sequences of the entire (1,143 bp) mitochondrial Cyt-b gene were obtained from each of the 41 species to facilitate comparison to the Adh 1-J2 data. PCR and sequencing primers, conditions, and thermal profiles followed Edwards and Bradley (2002) and Bradley et al. (2004a). Sequence alignments were performed manually and checked in MacClade software (version 4.05; Maddison and Maddison 2002) to ensure there were no insertions/deletions or stop codons in the protein¬ coding gene. Data analysis .—Analyses were performed in PAUP* 4.0b 10 software (Swofford 2002) or MrBayes 2.01 software (Huelsenbeck and Ronquist 2001). Nucleotide positions were treated as unor¬ dered, discrete characters (A, C, G, and T), multiple states as polymorphisms, and gaps as missing. Nucleotide sequences from both Adh \-12 and Cyt- b were evaluated four ways: 1) base frequencies, number of transitions, number of transversions, and number of substitutions per 100 bp were estimated within and compared among the five ingroup genera; 2) levels of phylogenetic signal were estimated using the -statistic (Hillis and Huelsenbeck 1992) for 100,000 randomly drawn trees; 3) genetic distances (uncorrected “p”) were obtained and compared using pairwise comparisons of taxa; and 4) maximum like¬ lihood, Bayesian likelihood, and parsimony analyses were performed and compared among taxa. Based on hierarchical likelihood ratio tests (hLRTs) in Modeltest software (Posada and Cran¬ dall 1998), the following models of nucleotide substitution and associated parameters best fit the data: Adh\-\2 —Hasegawa-Kishino-Yano (HKY) model with allowances for gamma distribution of rate variation (G), ti/tv = 2.308, JtA = 0.301, JtC = 0.191, jiG = 0.183, JtT = 0.325, a = 1.662; Cyt-b— general time reversible (GTR) with allowances for G and proportion of invariant sites (I), R A( = 1.310, R A( , = 10.479, R aT = 2.473, R C( . = 0.708, R ct = 32.137' JtA = 0.375, JtC = 0.343, jtG = 0.079, JtT = 0.203, a = 0.687, p - 0.456. The HKY + G model best fit the Adh 1 -12 data with and without ambiguous characters, although specific model parameters differed slightly; Adh\-\2 values reported were calculated without ambiguous characters. Bayesian analyses were run at least two mil¬ lion generations with four Markov-chains, random starting trees for each chain, and trees sampled every 100th generation. For each data set, two independent analyses were run to assess whether chains converged on the same posterior probability distribution and whether likelihood values became stable (Huelsenbeck et al. 2002). Model parameters were treated as unknown variables (with uniform priors) to be estimated in each Bayesian analysis (Leache and Reeder 2002). Burn-in values (initial set of unstable generations to be ignored) were based on empirical evaluation of likelihoods converging on stable values. Clade reliabilities were assessed using posterior probabilities (values > 0.95 regarded as significant). Maximum likelihood analyses were performed with full heuristic searches, neighbor-joining start¬ ing trees, and tree-bisection-reconnection branch swapping. Parsimony analyses, with all characters and substitution types given equal probabilities (i.e., unweighted), were conducted with full heuristic searches with 10 random additions, starting trees Amman et al.-Alcohol Dehydrogenase and Mammalian Systematics 5 by simple addition, and tree-bisection-reconnection branch swapping. Clade reliabilities were assessed in parsimony analyses using bootstrapping methods with 250 iterations (Felsenstein 1985). Due to pro¬ hibitive computation time under maximum likelihood, bootstrapping was performed for 100 iterations for just the Adh 1-12 dataset (100 iterations). Values > 70 were regarded as strong support. Results Adh/-/2 data .—Complete sequence of Adh 1- 12 averaged 530 bp for the 41 rodents examined, ranging from 494 ( Holochitm) to 576 (Peromyscus califoniicus). Alignment of sequences resulted in 614 aligned sites (125 ambiguously aligned) with the 5:4 gap cost-ratio, and 607 aligned sites (133 ambiguously aligned) with the 30:5 gap cost-ratio, corresponding to the insertion of more gaps with a lower cost ratio. As results from all subsequent analyses, phylogenetic analyses in particular, essentially were identical regard¬ less of alignment and with and without the ambiguously aligned characters excluded, only results based on the 5:4 alignment with 125 ambiguous characters removed are reported and discussed. After removing 125 ambiguous characters, 489 characters were available for analysis, of which 260 were constant and 126 were parsimony informative. Overall nucleotide frequencies varied slightly among the three genera (Table 2), averaging 30.47% (A), 17.51% (C), 17.94% (G), and 34.08% (T). The transi¬ tion to transversion ratio was approximately 2.28 to l. The number of heterozygous sites ranged from zero (37 taxa) to three (N. Stephensi, N. mexicana, and O. perenensis ), with a mean heterozygosity of 0.34 per taxon. The g ( statistic was skewed significantly left (-0.65; P< 0.01), indicating strong phylogenetic signal (Hillis and Huelsenbeck 1992). Cyt-b data .—^Complete sequences of Cyt-h (1,143 bp) were included for the 41 rodents examined herein. Sequence alignment was unequivocal and contained no stop codons. Of the 1,143 characters, 589 were constant and 475 parsimony informative. Nucleotide variation was distributed across codon positions as expected for protein-coding genes (1st position, 111; 2nd position, 37; 3rd position, 327). Overall nucleotide frequen¬ cies varied slightly among the three genera (Table 2), averaging 31.67% (A), 28.15% (C), 12.45% (G), and 27.74% (T), and transition to transversion ratio was approximately 2.68 to 1. Theg, statistic was skewed significantly left (-0.49; P < 0.01), indicating strong phylogenetic signal (Hillis and Huelsenbeck 1992). Phylogenetic analyses .—For ^4^/71 -12 and Cyt-b , Bayesian likelihoods reached stability before 100,000 generations (i.e., bum-in = 1,000), thinning the data to 19,000 sample points. Topology and posterior prob¬ abilities for nodes and model parameters for all sets of runs agreed. Maximum likelihood analysis resulted in a single best tree for both Adh\-\2 (Lnl = -2,718.63) and Cyt-b (Lnl = -14,379.92) data sets (Figs. 1 and 2). Table 2. Nucleotide base composition (A, C, G, and T), number of transition substitutions per 100 bp (#Ti/100 bp), number of transversion substitutions per 100 bp (#Tv/l 00 bp), and the uncorrected p distance (p Dist) for the 3 genera possessing multiple taxa. All values were averaged across taxa within each of the 3 genera for intron 2 of the alcohol dehydrogenase locus (AdhJ-I2) and the mitochondrial cytochrome-b gene (Cyt-b). Taxon/Sequence % A %C % G % T # Ti/100 bp # Tv/100 bp p Dist Peromyscus Adh\-\2 30.16 17.48 18.58 33.77 2.31 1.09 3.41% Peromyscus Cyt-b 31.72 27.45 12.62 28.21 8.38 2.79 12.29% Neotoma Adh 1 -12 30.35 17.73 17.59 34.33 1.67 0.50 2.22% Neotoma Cyt-b 32.24 28.93 12.43 26.40 8.73 2.90 11.61% Oryzomys Adh\-\2 31.34 17.33 16.97 33.37 4.48 2.10 6.70% Oiyzomys Cyt-b 31.16 28.43 11.98 28.43 7.73 5.75 14.00% 6 Occasional Papers, Museum of Texas Tech University Parsimony analysis resulted in 62 most-parsimonious trees (length = 363, Cl = 0.78, RI = 0.89) and a single most-parsimonious tree (length = 3,321, Cl = 0.28, RI = 0.48) for Adh 1-12 and Cyt-b, respectively. There were some topological differences within and between datasets and between the three optimality criteria, although only one difference between datasets represented a statistically supported conflict (i.e., > 70% bootstrap value, > 0.95 Bayesian posterior probability). This conflict involved the sister species relationships of N. albigula , N. leu codon, and N. micropus. Adh 1-12 supported a N. albigula/N. 1eucodon sister relationship, whereas Cyt-b supported a N. leucodon/N. micropus sister relationship (Figs. 2 and 3). Overall, statistically supported topologies obtained from all optimality cri¬ teria agreed within and between datasets, supporting monophyly of Neotoma and Peromyscus and diphyly o f Oryzo mys (Fig. 3). Discussion Results of this study indicated that Adh 1 -12 DN A sequences are useful for addressing phylogenetic re¬ lationships within and among the Sigmodontinae and Neotominae. Based on the g statistic and consistency and retention indices, the Adh 1 -12 dataset had a greater overall phylogenetic signal and less homoplasy than the Cyt-b dataset. Adh 1 -12 sequences also provided statistically supported resolution to slightly more re¬ lationships than Cyt-b (Fig. 3). For example, Adh 1 -12 strongly supported all relationships examined at and above the genus level, including monophyly of Neo¬ toma and Peromyscus and a sister relationship between Ototylomys and Tylomys , relationships that have been documented repeatedly by analysis of morphological and DN A sequence data (Carleton 1980; Bradley et al. 2004b; Edwards and Bradley 2002; Reeder and Bradley 2004, in press a and b). Adh 1-12 supported a diphyletic origin for Oryzo mys, a relationship also supported by Cyt-b and recent studies of nuclear markers (Myers and Tucker 1995; Smith and Patton 1993; Weksler 2003). It is particularly noteworthy that, compared with Cyt-b , the Adh\-\2 dataset provided supported resolu¬ tion to more species-level relationships within Neoto¬ ma , Peromyscus , and Oryzomys (Fig. 3), despite fewer overall characters (489 Adh 1-12, 1,143 Cyt-b) and fewer parsimony informative characters (126 Adh\-\2, 464 Cyt-b). Furthermore, all but one of the species-level relationships were congruent with results from Cyt-b. The exception involved the sister species relationships of N. albigula, N. Ieucodon , and N. micropus , and per¬ haps represented a situation of misleading phylogenetic inference. Whereas Adh 1-12 analysis provided strong support for a sister relationship between N. albigula and N. leucodon (parsimony, 98%; maximum likeli¬ hood, 94%; Bayesian, 100%), Cyt-b analysis strongly supported a sister relationship between N. leucodon and N. micropits (parsimony, 86%; Bayesian, 100%). The difference, however, is thatA/M -I[2 support was based on three characters, whereas Cyt-b support was based on 22 characters. We view these particular Adh 1-12 results with caution, and suggest additional study of nuclear markers will be necessary to help determine whether Adh 1-12 results accurately reflect a conflict between the mitochondrial and nuclear genomes or represents the case of misleading inference of relation¬ ship due to inadequate variability. Overall, the Adhi- 12 results are congruent with results from Cyt-b and other types of data, and gener¬ ally are accompanied by high statistical support. Fur¬ thermore, multiple sequence alignment, which can be problematic with non-coding DNA sequences (Giribet and Wheeler 1999; Hoofer and Van Den Bussche 2003; Van Den Bussche et al. 2002), was not of particular concern in this study. Although we identified 125 ambiguously aligned characters in the 5:4 alignment and 133 in the 30:5 alignment, results from analysis of both alignments with and without the ambiguous characters were identical in topology and statistical support. Thus, most of the phylogenetic signal in the Adh\-\2 dataset was associated with polymorphisms (nucleotide substitutions) rather than insertions/dele¬ tions. Yet, some insertion/deletions were informative. For example, a 5 bp (nucleotide positions 335-339) and a 4 bp (nucleotide positions 487-490) insertion/deletion were present in species of Oryzomys and Holochilus but absent in Neotoma and Peromyscus. Similarly, a 17 Amman et al.—Alcohol Dehydrogenase and Mammalian Systematics 7 Adh 1-12 — 0.01 substitutions/site O. albigularis — O. perenensis — O. melanotis — O. alfaroi O. couesi 0. palustris Holochilus ■ P. attwateri — P. difficilis L P. gratus |— P. melanophrys . *— P. perfulvus *— P. megalops - P. beatae P. boylii _ - P. hylocetes - P. levipes - P. schmidlyi L P. spicilegus - P. californicus -P. eremicus — P. leucopus -P. maniculatus — P crinitus — P. mexicanus — P. pectoralis r A/, leucodon '— A/, albigula ' — N. mexicana — N. goldmani j— N. floridana _ ' N. magister — N. micropus j— N. picta ' N. Isthmica N. Stephensi I- N. fuscipes N. cinerea *— N. lepida Ot. phyllotis - T. nudicaudus Figure 1, Maximum likelihood phylogram (Lnl -2,718.627) from analysis of 5:4 gap cost-ratio alignment of complete A dh \-12 sequences (489 base pairs; 614 aligned sites minus 125 ambiguously aligned sites) using best-fit model (HKY + G; ti/tv = 2.308, jiA = 0.301, jtC = 0.191, jtG = 0.183, JtT = 0.325, a = 1,662). Holochilus was the designated outgroup. N. = Neotoma. O. ~ Oryzomys. Of. Ototylomys, P. = Peromyscus. T = Tylomys. 8 Occasional Papers, Museum of Texas Tech University Cyt-b — 0.05 substitutions/site N. floridana N. magister pj 1 — N. albigula - N. goldmani N. leucodon N. micropus r~ N. picta L^— N. isthmica — N. mexicana - N. cinerea t_ N — N. stephensi ■ N. fuscipes ■ N. lepida — Ot. phyllotis ■ T. nudicaudus - P. leucopus P. maniculatus I - P. melanophrys P. perfulvus — P. mexicanus t' P. megalops P. attwateri P. difficilis P. pectoralis r P. beatae L P. levipes P. schmidlyi ■ P. boylii j - P. hylocetes — P. spicilegus — P. gratus ~P. californicus ■ P. eremicus ■ P. crinitus — O. alfaroi — O. melanotis O. perenensis — O. albigularis I O. couesi O. palustris ■ Holochilus Figure 2. Maximum likelihood phylogram (Lnl -14,379.922) from analysis of complete Cyt-b sequences (1,143 base pairs) using best-fit model (GTR + G + I; R M , = 1.310, R Afi = 10.479, R A1 - 2.473, R ( ,. = 0.708, R rT = 32.137, JtA = 0.375, jrC - 0.343, jtG - 0.079. JtT = 0.203, a = 0.687, 7 lO C7 p w ~ 0.456). Holochilus was the designated outgroup. N. ^ Neotoma. O. ~ Oryzomys. Ot. =* Ototylomys. P. = Peromyscus. T. =- Tylomys. Amman et al.—Alcohol Dehydrogenase and Mammalian Systematics 9 P. beatae P. levipes P. schmidlyi P. boylii P. hylocetes P. spicilegus P. attwateri P. difficilis P. gratus P. megalops P. melanophrys P. perfulvus P. mexicanus P. californicus P. eremicus P. leucopus P. maniculatus P. pectoralis P. crinitus N. goldmani N. magister N. floridana N. albigula N. leucodon N. micropus N. fuscipes N. cinerea N. lepida N. mexicarta N. picta N. isthmica N. stephensi Ot. phyllotis T. nudicaudus O, albigularis O. perenensis O. melanotis O. alfaroi O. couesi O. palustris Holochilus Figure 3. Cladograms from phylogenetic analyses of complete ^<^1-12 (left) and Cyt-b (right) DNA sequences. Holochilus was the designated outgroup. In order, numbers above and below nodes are bootstrap proportions (250 iterations) from parsimony analysis, bootstrap proportions (100 iterations) from maximum likelihood analysis, and posterior probability proportions from Bayesian analysis, Maximum likelihood bootstrapping was feasible only for Adh\-\2 data. Only nodes with >70% bootstrap support or >0.95 posterior probabilities, or both, are shown. Vertical dotted line indicates sister relationship between N. micropus and clade of A’, floridana + N. magister. N. = Neotoma . O. = Oiyzomys. Ot. = Ototylomys. P. = Peromyscus. T. = Tylomys. 10 Occasional Papers, Museum of Texas Tech University bp insertion/deJetion (nucleotide positions 502-518) was present in Neotoma and Pero my setts but was ab¬ sent in Oryzomys and Holochilus. These results are encouraging toward the goal of recovering reliable phylogenetic relationships at low and intermediate taxonomic levels from a nuclear intron. Further study of this intron, along with other nuclear and mitochondrial markers, should aid our understand¬ ing of the phyletic limitations of Adh\-Y2 as well as organismal genealogy. Acknowledgments Thanks to B. Dnate Baxter, Nevin D. Durish, Michelle L. Haynie, Dallas D. Henson, Lindsey D. Porr, Andrew O. Stallings, Ryan R. Chambers, and two anonymous reviewers for providing helpful comments on previous versions of this manuscript. Thanks to Robert J. Baker for use of laboratory equipment and computers during various stages of this study. This research was supported by a grant from the National Institutes of Health (DHHS A141435-01 to RDB). Literature Cited Anderson, S., A, T. Bankier, B. G. Barrell, M. H. de Bruijn, A. R. Coulson, J. Drouin, I. C. Eperon, D. P. Nierlicj, B. A. Roe, F. Sanger, P. H, Schreier, A. J. Smith, R. Staden, and 1. G. Young. 1981. Sequence and organization of the human mitochondrial genome. Nature 290:457-465. Avise, J. C. 1994. Molecular markers, natural history, and evolution. Chapman and Hall, New York. Ballard, J, W., B. Chernoff, and J. C. Avise. 2002. Diver¬ gence of mitochondrial DNA is not corroborated by nuclear DNA, morphology, or behavior in Dro¬ sophila simulam. Evolution 56:527-545. Bradley, R. D., J. J. Bull, A. D. Johnson, and D. M. Hillis. 1993. Origin of a novel allele in a mammalian hybrid zone. Proceedings National Academy of Science 90:8939-8941. Bradley, R. D., R. M. Adkins, R. L. Honeycutt, and J. H. McDonald. 1998. Nucleotide polymorphism at the alcohol dehydrogenase locus of pocket gophers, genus Geomys. Molecular Biology and Evolution 15:709-717.’ Bradley, R. D., D, S, Carroll, M. L. Haynie, R. Muniz- Martinez, M. J. Hamilton, and C. W. Kilpatrick. 2004a. A new species of Peromyscus from western Mexico. Journal of Mammalogy 85:1184-1193. Bradley, R. D., C. W. Edwards, D. S. Carroll, and C. W. Kilpatrick. 2004b. Phylogenetic relationships of Neotomine-Peromyscine rodents: based on DNA sequences from the mitochondrial cytochrome h gene. Journal of Mammalogy 85:389-395. Carleton, M. D. 1980. Phylogenetic relationships in ne- otomine-peromyscine rodents (Muridae) and a reappraisal of the dichotomy within New World cricetinae. Miscellaneous Publications, Museum of Zoology, University of Michigan 157:1-146. Carroll, D. S., and R. D. Bradley. 2005. Systematics of the genus Sigmodon: DNA sequences from beta- fibrinogen and cytochrome-6. The Southwestern Naturalist 50:342-349. Collins, T., P H. Wimberger, and G. J. P. Naylor. 1994. Compositional bias, character-state bias, and character-state reconstruction using parsimony. Systematic Biology 43:482-496. Crabb, D, W., and H. J. Edenberg. 1986. Complete amino acid sequence of rat liver alcohol dehydrogenase deduced from the cDNA sequences. Gene 48:287- 292. Crabb, D. W., P. M. Stein, K. M. Dipple, R. Sidhu, K. Zhang, and H. J. Edenberg. 1989. Structure and expres¬ sion of the Rat Class I alcohol dehydrogenase gene, Genomics 5:906-914, DeSalle, R., C. Wray, and R. Absher. 1994. Computational problems in molecular systematics. Pp. 353-370 in Molecular ecology and evolutions: Approaches and applications (B. Schierwater, B. Streit, G. P Wagner, and R. DeSalle, eds.). Birkhauser Verlag Basel, Switzerland. Desjardins, P, and R. Morais. 1990. Sequence and gene organization of chicken mitochondrial genome. Journal of Molecular Biology 212:599-634. Amman et al.-Alcohol Dehydrogenase and Mammalian Systematics 11 Dolney, D. E. A., G. Szalai, G. Duester, and M. R. Felder. 2001. Molecular analysis of genetic differences among inbred mouse strains controlling tissue expression pattern of alcohol dehydrogenase 4. Gene 267:145-156. Duester, G., J. Farres, M. R, Felder, R. S. Flolmes, J. Hoog, X. Pares, B. V. Plapp, S. Yin, and H. Jdmvall. 1999. Recommended nomenclature for the vertebrate alcohol dehydrogenase gene family. Biochemical Pharmicology 58:389-395. Edwards, C. W. and R. D. Bradley. 2002. Molecular sys- tematics of the genus Neotoma. Molecular Phylo¬ genetics and Evolution 25:489-500. Felsenstein, J. 1985. Confidence limits on phylogemes: An approach using the bootstrap. Evolution 39:783-791. Fonseca, R.M, S.R. Hoofer, C.A. Cline, D.A. Parish, F.G. Hoffmann, C.A. Porter, and R.J. Baker. In press. Comments on the morphological variation in dark- bellied species of Micronycteris (Phyllostomidae: Micronycterinae), with description of a new spe¬ cies from northwestern Ecuador. Pp. xxx-xxxx in The quintessential naturalist: honoring the life and legacy of Oliver P. Pearson (D.A. Kelt, E, Lessa, J. A. Salazar-Bravo, and J.L. Patton, eds.). Univer¬ sity of California Press. Giribet, G., and W. C. Wheeler. 1999. On gaps. Molecular Phylogenetics and Evolution 13:132-143. Gouy, M., and W.-H. Li. 1989. Phylogenetic analysis based on rRNA sequences supports the archaebacterial rather than the eocyte tree. Nature 339:145-147. Hafner, M. S., W. L. Gannon, J. Salazar-Bravo, and S. T. Alvarez-Castaneda. 1997. Mammal collections in the western hemisphere: a survey and directory of existing collections. Allen Press, Lawrence, Kansas. Helbig, A. J., A. Kocum, I. Seibold, and M. J. Braun. 2005. A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level. Molecular Phylogenetics and Evolu¬ tion 35:147-164. Hickson, R, E., C. Simon, and S. W. Perrey. 2000. The performance of several multiple-sequence align¬ ment programs in relation to secondary-structure features for an rRNA sequence. Molecular Biology and Evolution 17:530-539. Hillis, D. M., C. Moritz, and B. K. Mable. 1996. Molecular systematics (D. M, Hillis, C. Moritz and B. K. Mable, eds.) Second edition. Sinauer and Associ¬ ates, Sunderland, Massachusetts, Hillis, D. M., and J. P. Huelsenbeck. 1992. Signal, noise, and reliability in molecular phylogenetic analyses. Journal of Heredity 83:189-195. Hoofer, S. R., and R. A. Van Den Bussche. 2003. Mo¬ lecular phylogenetics of the chiropteran family Vespertilionidae. Acta Chiropterologica 5 (supple¬ ment): 1-63. Huelsenbeck, J. P., and F. Ronquist. 2001. Mr.Bayes: Bayesian inference of phylogeny. Bioinformatics 17:754-755. Huelsenbeck, J. P., B. Larget, R. E. Miller, and F. Ronquist. 2002. Potential applications and pitfalls of Bayes¬ ian inference of phylogeny. Systematic Biology 51:673-688. Ikuta, E., S. Szeto, and A. Yoshida. 1986. Three human alcohol dehydrogenase subunits: cDNA structure and molecular and evolutionary divergence. Pro¬ ceedings of the National Academy of Sciences 83:634-638. Jackson, P. D., and F. M. Hoffmann. 1994. Embryonic ex¬ pression patterns of the Drosophila decapentaplegic gene: separate regulatory elements control blasto¬ derm expression and lateral ectodermal expression. Developmental Dynamics 199:28-44. Johansson, U. S., and P. G. P. Ericson. 2004. A re-evalu¬ ation of basal phylogenetic relationships within trogons (Aves: Trogonidae) based on nuclear DNA sequences. Journal of Zoological Systematics and Evolutionary Research 43:166-173. Lavoue, S., J. P. Sullivan, and C. D. Hopkins. 2003. Phy¬ logenetic utility of the first two introns of the S7 ribosomal protein gene in African electric fishes (Mormyroidea: Teleostei) and congruence with other molecular markers. Biological Journal of the Linnean Society 78:273-292, Leache, A. D., and T. W. Reeder. 2002. Molecular sys¬ tematics of the eastern fence lizard (Sceloporus undidatiis): a comparison of parsimony, likelihood, and Bayesian approaches. Systematic Biology 51:44-68. Lockhart, P. J., M. A. Steel, M. D. Hendy, and D. Penny. 1994. Recovering evolutionary trees under a more realistic model of sequence evolution. Molecular Biology and Evolution 11:605-612. Lutzoni, F., P. Wagner, V. Reeb, and S. Zoller. 2000. In¬ tegrating ambiguously aligned regions of DNA sequences in phylogenetic analyses without vio¬ lating positional homology. Systematic Biology 49:628-651. 12 Occasional Papers, Museum of Texas Tech University Maddison, D. R., and W. P. Maddison. 2002. MacClade 4 (version 4.05). Sinauer Associates, Sunderland, Massachusetts. Musser, G. G., and M. D. Carleton. 2005. Superfamily Muroidea. Pp. 894-1531 in Mammal species of the world: a taxonomic and geographic reference. Third edition (D. E. Wilson and D. M. Reeder, eds.). The Johns Hopkins University Press, Baltimore, Maryland. 2 vols. Myers, P., B. Lundrigan, and P. K. Tucker. 1995. Molecular phylogenetics of oryzomyine rodents: the genus Oligoiyzomys. Molecular Phylogenetics and Evo¬ lution 4:372-382. Oakley, T. H., and R. B. Phillips. 1999. Phylogeny of sal- monine fishes based on growth hormone introns: Atlantic ( Salmo) and Pacific ( Oncorhynchus) salmon are not sister taxa. Molecular Phylogenetics and Evolution 11:381-393. Park, D. H., and B. V. Plapp. 1991. Isoenzymes of horse liver alcohol dehydrogenase active on ethanol and steroids. cDNA cloning, expression, and compari¬ son of active sites. Journal of Biological Chemistry 266:13296-13302. Perasso, R., A. Baroin, L.H. Qu, J. Bachellerie, and A. Adoutte. 1989. Origin of the algae. Nature 339:142-144. Pema, N. T., and T. Kocher. 1995. Unequal base frequen¬ cies and estimation of substitution rates. Molecular Biology and Evolution 12:359—361. Porter, C. A., S. R. Hoofer, C. A. Cline, F. G. Hoffmann, and R. J. Baker. In review. Molecular phylogenetics of the genus Micronycteris (Phyllostomidae: Micro- nycterinae) with description of 2 new subgenera. Journal of Mammalogy. Posada, D. and K. A. Crandall. 1998, MODELTEST: testing the model of DNA substitution. Bioinformatics 14:817-818. Prychitko, T. M., and W. S. Moore. 1997. The utility of DNA sequences of an intron from the beta-fibrino¬ gen gene in phylogenetic analysis of woodpeckers (Aves: Picidae). Molecular Phylogenetics and Evolution 8:1993-204. Prychitko, T. M., and W. S. Moore. 2000. Comparative evolution of the mitochondrial cytochrome b gene and nuclear b-fibrinogen intron 7 in woodpeckers. Molecular Biology and Evolution 17:1101-1 111. Reeder, S. A., and R. D. Bradley. 2004. Molecular System- atics of Neotomine-Peromyscine Rodents Based on the dentin matrix protein 1 gene. Journal of Mammalogy 85:1194-1200. Reeder, S. A., and R. D. Bradley. In Press a. Phylogenetic relationships of Neotomine-Peromyscine rodents using DNA sequences from intron 7 of the beta fibrinogen gene. Pp. xxx-xxx in The quintessential naturalist: honoring the life and legacy of Oliver P Pearson (D. A. Kelt, E. Lessa, J. L. Patton, and J. A. Salazar-Bravo eds.). University of California Publications in Zoology. Reeder, S, A., C. W. Edwards, D. S. Carroll, and R. D. Brad¬ ley. In Press b. Neotomine-Peromyscine rodent systematics based on combined analyses of nuclear and mitochondrial DNA sequences. Molecular Phylogenetics and Evolution. Roe, B. A., D.-P. Ma, R. K. Wilson, and J. F.-H. Wong. 1985. The complete nucleotide sequence of the Xenopus laevis mitochondrial genome. Journal of Biological Chemistry 260:9759-9774. Saiki, R. K„ D. H. Gelfand, S. Stoffel, S. J. Scharf, R. Hi- guchi, G. T. Horn, K. B, Mullis, and H. A. Erlich. 1988. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Sci¬ ence 239:487-491. Slade, R. W., C. Moritz, and A. Heideman. 1994. Multiple nuclear-gene phylogenies: applications to pinnipeds and comparisons with a mitochondrial DNA gene phylogeny. Molecular Biology and Evolution 11:341-356. Smith, M. F., J. L. Patton. 1993. The diversification of South American murid rodents: evidence from mi¬ tochondrial DNA sequence data for the akodontine tribe. Biological Journal of the Linnean Society 50:149-177. Smith, M. F., and J. L. Patton. 1999. Phylogenetic relation¬ ships and the radiation of sigmodontine rodents in South America: evidence from cytochrome b. Journal of Mammalian Evolution 6:89-128. Swofford, D. L. 2002. PAUP*: phylogenetic analysis using parsimony (*and other methods) version 4.0b 10. Sinauer Associates, Sunderland, Massachusetts. Szalai, G., G. Duester, R. Friedman, H. Jia, S. Lin, B. A, Roe, and M. R. Felder. 2002. Organizations of six functional mouse alcohol dehydrogenase genes on two overlapping bacterial artificial chromosomes. European Journal of Biochemistry 269:224-232. Thompson, J. D., T. J. Gibson, F. Plewniak, F. Jean-mougin, and D. G. Higgins. 1997. The Clustal X window interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Research 25:4876-4882. Amman et al.-Alcohol Dehydrogenase and Mammalian Systematics 13 Van Den Bussche, R. A., and S. R, Hoofer. 2001. Evaluat¬ ing monophyly of Nataloidea (Chiroptera) with mitochondrial DNA sequences. Journal of Mam¬ malogy 82:320-327. Van Den Bussche, R. A., S. R. Hoofer, and E. W. Hansen. 2002. Characterization and phylogenetic utility of the mammalian protamine PI gene. Molecular Phylogenetics and Evolution 22:333-341. Weksler, M. 2003. Phylogeny of neotropical oryzomyine rodents (Muridae: Sigmodontinae) based on the nuclear IRBP exon. Molecular Phylogeny and Evolution 29:331-349. Wheeler, W. C, 1995. Sequence alignment, parameter sen¬ sitivity, and the phylogenetic analysis of molecular data. Systematic Biology 44:321-331. Addresses of authors: Addresses for Brian R. Amman, J. Delton Hanson, Lisa K. Longhofer, Steven R. Hoofer, and Robert D. Bradley: Department of Biological Sciences Texas Tech University Lubbock, Texas 79409-3131 BRA e-mail: bamman@cdc.gov JDH e-mail: j delton. hanson@ttu. edu LKL e-mail: brombel4@hotmail.com SRH e-mail:srhoofer@hotmail. com RDB e-mail: robert.bradley@ttu.edu Current Address for Brian R. Amman: Centers for Disease Control and Prevention Division of Viral and Rickettsial Diseases Special Pathogens Branch Atlanta, GA 30333 Wicldiffe, J. K„ F. G. Hoffmann, D. S. Carroll, Y. V. Dunina- Barkovskaya, R. D. Bradley, and R. J. Baker. 2003. Intron 7(Fgb-17) of the fibrinogen, B beta polypep¬ tide (Fgb): a nuclear DNA phylogenetic marker for mammals. Occasional Papers, Museum of Texas Tech University 219:i+1 -6. Zhang, K., W. F. Bosron, and H. J. Edenberg. 1987. Struc¬ ture of the mouse Adh -1 gene and identification of a deletion in a long alternating purine-pyrimidine sequence in the first intron of strains expressing low alcohol dehydrogenase activity. Gene 57:27-36. Zheng, Y.-W., M. Bey, H. Liuand, and M. R. Felder. 1993. Molecular basis of the alcohol dehydrogenase-neg¬ ative deer mouse. Journal of Biological Chemistry 268:24933-24939. Current Address for Lisa K. Longhofer: Texas Tech University Health Sciences Center Texas Tech University Lubbock, Texas 79409 Address for Robert D. Bradley: Department of Biological Sciences and Museum of Texas Tech University Lubbock, Texas 79409-3191 14 Occasional Papers, Museum of Texas Tech University Appendix I Specimens examined. — Collection localities, museum acronyms, and GenBank accession numbers are provided for each specimen examined in this study. Specimens are from the United States unless otherwise noted. Abbreviations for museum acronyms (in parentheses and to the left of the semicolon) follow Hafner et al. (1997): Abilene Christian University Natural History Collection (ACUNHC), Angelo State University Museum Natural History Collections (ASNHC), Monte L. Bean Life Science Museum (BYU), Texas Cooperative Wildlife Col¬ lection (TCWC), Museum of Texas Tech University (TTU), The Museum of Southwestern Biology (MSB), and Universidad Nacional Autonoma de Mexico (UNAM). If museum catalogue numbers were unavailable, specimens were referenced with the corresponding TK number ( special number of the Museum of Texas Tech University). GenBank accession numbers (AF, AY, U, and DQ) for Adh 1-12 and Cyt-b are provided in parentheses to the right of the semicolon and separated by a comma, respectively. Holochilus chacarius. —PARAGUAY: Department Pte. Hayes; Estancia Loma Pora, 23°33.15’S, 57°34.3’W (TTU104423; DQ227456, DQ227455). Neotoma albigula. —New Mexico; Yuma Co., 3.7 km S, 5.6 km W Somerton, UTM 11 708569E 3608362N (TTU78451; AY817648, AF376477). Neotoma cinerea. —Utah; San Juan Co., Owaehamo Bridge (MSB 121427; AY817635, AF 186799). Neotoma fioridana. —South Carolina; Richland Co.. Congaree Swamp National Monument, 33°49’N, 80°50’W (MSB74955; AY817637, AF294335). Neotoma fuscipes. —California; Riverside Co., Rancho Capistrano (Ortega Mountains) (TTU81391, AY817632, AF376479). Neotoma goldmani. —MEXICO: Nuevo Leon; 1 km S Providencia (TTU45227; AY817656, AF 186829). Neotoma isthmica — MEXICO: Oaxaca; Las Minas, UTM 15 191165E 1824954N (TTU82665; AY817630, AF329079). Neotoma lepida. —California; Orange Co., Irvine Lake, 1.3 km E Fremont Canyon on Lake View access road (TTU79131; AY817633, AF307835). Neotoma leucodon. —Texas; Kerr Co., Kerr Wildlife Management Area, UTM 14 452336E 3330772N (TTU71198; AY817643, AF 186806). Neotoma magister .— Virginia; Madison Co., Shenendoah National Park, White Oak Canyon, 38°34’36”N, 78 o 22’30”W (MSB74952; AY817641, AF294336). Neotoma mexicana .— Texas; Jeff Davis Co., Mount Livermore Preserve, UTM 13 579953E 3389871N (TTU101643; AY817645, AF294346). Neotoma micropus.— New Mexico; Roosevelt Co., 26.4 km S, 4.8 km E Taiban (TTU catalogue number unavailable, TK31643; AY817652, AF 186822). Neotomapicta .— MEXICO: Guerrero; 6.4 km SSW Filo de Caballo (UNAM catalogue number unavailable, TK93390; AY817629, AF305569). Neotoma stephensi— Arizona; Navaho Co., 4.8 km S Woodruff, UTM 12 588361E 3844338N (TTU78505; AY817642, AF308867). Ofjzomys albigularis .— ECUADOR: Pichincha; 10 km NW Quito, Tandayapa Valley, 0°00’13”N, 78 o 40’70”W (ACUNHC917; DQ207945, DQ224407). Otyzomys alfaroi.— NICARAGUA: Selava Negra; Altajo Trail (TTU 101644; DQ207950, DQ224410). Amman et al.-Alcohol Dehydrogenase and Mammalian Systematics 15 Appendix I (cont.) Oryzomys coitmi. —HONDURAS: Olancho; 4 km E Catacamas (Escuelade Sembrador), UTM 16 624523E 163751 IN (TTU84697; DQ207948, DQ185383). Oryzomys melanotis. —HONDURAS: Atlantida; Lancetilla Botanical Gardens, UTM 16 451012E 1740282N (TTU84374; DQ207947, DQ224409). Oryzomys pains trish-Texas\ Galveston Co., Texas City, Virginia Point (TTU82920; DQ207949. DQ 185382). Oryzomys perenensis — PERU: Loreto; Maynas, 25 km S Iquitos (Estacio Biologia Allpahuayo) (TTU98606; DQ207946, DQ224408). Ototylomys phyllotis. — HONDURAS: Atlantida; Lancetilla Botanical Gardens, UTM 16451012E 1740282N (TTU84371; AY817624, no Cyt-b data); MEXCIO: Quintana Roo, 1 km N Noh-bec (ASNHC7254; no Adh\-\2 data. AY009788). Peromyscus attwateri. —Oklahoma; McIntosh Co., 5 km E Dustin (TTU55688; AY817626, AF155384). Peromyscns beatae. —MEXICO: Chiapas, Yalentay, UTM 15 52417 IE 1852486N (UNAM catalogue number unavailable, TK93279; AY994223, no Cyt-b data); Veracruz; Xometla (TCWC48060; mAdh\-\2 data, AF131921). Peromyscus boylii. —California; San Diego Co., Heise County Park (TTU83102; AY994225, no Cyt-b data); MEXICO: Aguascali- entes; Rincon de Romos (TCWC48438; no Adh 1-12 data, AF 131924). Peromyscus californicus. —California; Los Angeles Co., Chatsworth Resevoir Park (TTU83292; AY994211, AF 155393). Peromyscus crinitus. —Utah; Emery Co., Cottonwood Canyon, 39° 16’5 1.8”N, 111°10’31.9”W (BYU18639; AY994213, AY376413). Peromyscus difficilis. —MEXICO: Tlaxcala; 2 km NE Tepetitla (TTU82690; AY994219, AY376416). Peromyscus eremicus, —California: Los Angeles Co., Kanan Dome Road (TTU81850; AY994212, no Cyt-b data); California; Los Angeles Co., Calabasas Creekside Park (TTU83249; no Adh]-12, AY322503). Peromyscus gratus — MEXICO: Michoacan; 4 km E Costzeo (UNAM catalogue number unavailable, TK46354; AY994218, AY376421). Peromyscus hylocetes. —MEXICO: Michoacan; Estacion Cerra Burror, Microodas; 3,270 m (UNAM catalogue number unavailable, TK 45309; AY994235, DQ000481). Peromyscus leucopus. —Texas; Presidio Co., Las Palomas Wildlife Management Area, UTM 13 52948 IE 3321292N (TTU75694; AY994240, no Cyt-b data); Dickens Co., 0.9 km E Afton (TTU catalogue number unavailable, TK47506; no Adh 1-12 data, AF131926). Peromyscus levipes. —MEXICO: Michoacan, Las Minas, 3 km SW Tuxpan (UNAM catalogue number unavailable, TK47819; AY994224, DQ000477). Peromyscus maniculatus. —Arkansas; Mississippi Co., Dillahunty Pecan Orchard (TTU97830; AY994242, no Cyt-b data); Alaska, Alexander Archipelago, Bushy Island, Petersburg Quad, 56°15’45 ,r N, 132°58’52”W (UAM50770; noAdh\-\2 data, AF119261). Peromyscus megalops.— MEXICO: Guerrero; 6.4 km SSW Filo de Caballo (TTU82712; AY994217, DQ000475). Peromyscus meianophrys. —MEXICO: Durango; 2.2 km S, 2.5 km E Vicente Guerrero (TTU75509; AY994216, AY322510). Peromyscus mexicamts .— MEXICO; Chiapas; 14.4 km N Ocozocoaulta (TTU82759; AY994236, AY376425). Appendix I (cont.) Peromyscus pectoralis .—MEXICO: Jalisco; 30 km W Huejuquilla del Alto (UNAM catalogue number unavailable, TK48645; AY994221, no Cyt-b data; TTU75575; no Adh\ 42 data, DQ000476). Peromyscus perfitlvus.— MEXICO: Michoacan; Tunel de Riego, 2 km E Cerro Colorado, 1290 M, 19°19'220”N, 100°28 , 308”W (UNAM catalogue number unavailable, TK47926; AY994215, DQ000474). Peromyscus schmidlyi '—MEXICO: Durango; 6.1 km W Coyotes, Hacienda Coyotes, UTM 13 465908E 2634281N (TTU81617; AY994228, AY322524). Peromyscus spicilegus .—MEXICO: Michoacan; KM 81 carr., Ario de Rosales-La Huacana, 1602 m, 19°10’59”N, 101°43’42”W (UNAM catalogue number unavailable, TK 47888; AY994232, DQ000480). Tylomys mtdicaiidatus.— GUATEMALA: lzabal, Cerro San Gil (TTU62082; AY817625, AF307839). TEXAS TECH UNIVERSITY Natural Science Research Laboratory Publications of the Museum of Texas Tech University Institutional subscriptions are available through the Museum of Texas Tech University, attn; NSRL Publications Secretary, Box 43191, Lubbock, TX 79409-3191. Individuals may also purchase separate numbers of the Occasional Papers directly from the Museum of Texas Tech University. ISSN 0149-175X Museum of Texas Tech University, Lubbock, TX 79409-3191