Herpetologists' League Albumin Evolution and Its Phylogenetic Implications in the Plethodontid Salamander Genera Pseudoeurycea and Chiropterotriton Author(s): Linda R. Maxson and David B. Wake Source: Herpetologica, Vol. 37, No. 2 (Jun., 1981), pp. 109-117 Published by: Allen Press on behalf of the Herpetologists' League Stable URL: http://www.jstor.org/stable/3891767 Accessed: 03-02-2016 22:17 UTC REFERENCES Linked references are available on JSTOR for this article: http://www.jstor.org/stable/3891767?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Herpetologists' League and Allen Press are collaborating with JSTOR to digitize, preserve and extend access to Herpetologica. http://www.jstor.org This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 22:17:42 UTC All use subject to JSTOR Terms and Conditions Herpetologica, 37(2), 1981, 109-117 ? 1981 by The Herpetologists' League, Inc. ALBUMIN EVOLUTION AND ITS PHYLOGENETIC IMPLICATIONS IN THE PLETHODONTID SALAMANDER GENERA PSEUDOEURYCEA AND CHIROPTEROTRITON LINDA R. MAXSON AND DAVID B. WAKE ABSTRACT: The immunological technique of quantitative micro-complement fixation was used to study albumin evolution in the plethodontid salamander genera Pseudoeurycea and Chiropterotriton from Mexico and Central America. Antisera were prepared for representatives of the five species-groups of Pseudoeurycea and for the a and f3 groups of Chiropterotriton. A matrix of reciprocal tests was used to construct a dendrogram illustrating probable relationships. The a and p groups of Chiropterotriton are as distant from each other as they are from Pseu- doeurycea. The rex and gadovii groups of Pseudoeurycea are not well differentiated, and uni- directional tests to 13 additional species of Pseudoeurycea indicate that many species have been incorrectly assigned to groups. Pseudoeurycea cephalica is especially remote from all other species of Pseudoeurycea tested; it is even more remote from the species of Chiropterotriton tested. The cephalica, leprosa, and bellii groups are all well distinguished from each other and from the gadovii (including rex) group. Within Chiropterotriton p the bromeliacia and picadoi groups are sharply distinguished from each other. The great range of immunological distance measured in this study (from 0 to over 100) indicates that both of these genera are as differentiated genetically as is the North American genus Plethodon, and that the evolutionary history of each of these genera encompasses most of Cenozoic time. Key words: Albumin, Amphibia, Caudata, Chiropterotriton, Phylogeny, Pseudoeurycea NEARLY hal-f of the living salamanders Of the eight genera currently recog- are presently included in one taxon-the nized in the supergenus Bolitoglossa, supergenus Bolitoglossa of the tribe Bo- Pseudoeurycea and Chiropterotriton are litoglossini, family Plethodontidae. This the most generalized in morphology (see exclusively tropical group is found only review in Wake and Lynch, 1976). We in the New World; its only close relatives have chosen them for a detailed investi- are the genera Hydromantes and Batra- gation of albumin evolution, using the choseps, both of which are inhabitants of quantitative immunological technique of western North America (Hydromantes micro-complement fixation (MC'F). In occurs in Europe as well). The supergen- previous work we used this technique in us Bolitoglossa is considered to be the conjunction with starch-gel electropho- most derived lineage of salamanders, and resis and morphology to analyze salaman- has undergone an extensive adaptive ra- der phylogeny (Larson et al., 1981; Max- diation (Wake and Lynch, 1976). The re- son and Maxson, 1979; Maxson et al., lationships of its component lineages are 1979; Wake et al., 1978). Electrophoretic poorly understood, for there is no fossil and morphological analyses relevant to record and there has been extensive mor- the present study will be reported else- phological parallelism and convergence where. (Wake, 1966). Attempts are being made The 23 described species of Pseudoeu- to integrate diverse kinds of data into a rycea are placed in five species-groups, coherent picture of relationships; the four of which occur only in Mexico. The present report is the first to deal with fifth group is mainly Guatemalan, but two macromolecular evolution in the group. species enter Chiapas, Mexico. We se- 109 This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 22:17:42 UTC All use subject to JSTOR Terms and Conditions 110 HERPETOLOGICA [Vol. 37, No. 2 TABLE 1.-Salamanders of the genus Pseudoeury- TABLE 2.-Salamanders of the genus Chiroptero- cea (after Wake and Lynch, 1976). triton (after Wake and Lynch, 1976). Species Chiropterotriton a Chiropterotriton O group Species multidentatus species- bromeliacia species- bellii P. belliia,b group group cephalica P. cephalicaa,b P. conanti C. multiden- C. bromeli- P. cochranaeb P. galeanae tatusab aciaa,b P. werlerib P. scandensb C. arboreus C. cuchu- P. altamontanab C. magnipes matanusb gadovii P. gadoviib P. unguidentisb C. mosauri C. rabbib P. smithia,b P. melanomolgab C. xolocalcae C. megarhinus leprosa P. leprosaa,b P. robertsib P. anitae P. firscheini chiropterus species- picadoi species- P. juarezib P. mystax group group P. nigromacu- C. chiropterusb C. picadoi latab C. chondro- C. richardi stegab C. nasalisb rex P. reXb P. goebelib C. dimidiatusb C. barbouri P. brunnataa,b P. exspectatab C. lavae C. veraepacisb a Albumin purified and antisera prepared. 'Albumin samples extracted. priscus species-group C. priscusb a Albumin purified and antisera prepared. b Albumin samples extracted. lected one member of each species-group for preparation of antisera (Table 1). Two groups of essentially generic level are MATERIALS AND METHODS recognized in Chiropterotriton (Lynch Plasma (preserved in phenoxyethanol) and Wake, 1978; Wake and Lynch, 1976). from 18 species of the genus Pseudoeu- The a group is restricted to the moun- rycea and 10 species of the genus Chi- tains of eastern Mexico, north of the Isth- ropterotriton was used as a source of al- mus of Tehuantepec. There are three bumin. Voucher specimens of all species species-groups and nine species in Chi- are in the Museum of Vertebrate Zoolo- ropterotriton a; we prepared antisera to gy, University of California, Berkeley. one species (Table 2). Chiropterotriton Albumin was purified from plasma of /l is mainly Central American in distri- five species of Pseudoeurycea (Table 1) bution; it occurs from just south of the and two species of Chiropterotriton (Ta- Isthmus of Tehuantepec to the Meseta ble 2). Due to the small size of the ani- Central of Costa Rica. There are two mals, plasma from several members of species-groups and 10 species; we pre- the same population was pooled. Purifi- pared antisera to one species (Table 2). cation was by single-step, polyacrylam- Because most species of Pseudoeurycea ide-gel electrophoresis (Maxson et al., and Chiropterotriton are small, rare, or 1979). Albumin was identified by its flu- both, it was impractical to produce more orescence in the presence of 8-anilino-1- antisera. However, the number of anti- napthalene sulfonate (Hartman and sera available was adequate to investi- Udenfriend, 1969). gate the relationships of the genera and Antisera to pure albumins were pre- the major species-groups. While we em- pared in male Dutch Belted rabbits by phasize those species for which tests of the following procedure. Rabbits re- reciprocity are presently possible, we ceived an initial intradermal injection of also report unidirectional tests for a num- Freund's complete adjuvant and albumin ber of other species belonging to the ma- (1.2:1). This was followed at 7 weeks by jor groups studied. an intradermal injection of Freund's in- This content downloaded from 136.152.142.101 on Wed, 03 Feb 2016 22:17:42 UTC All use subject to JSTOR Terms and Conditions June 1981] HERPETOLOGICA 111 TABLE 3.-Matrix of immunological distances among albumins of species of plethodontid salamanders of the genera Pseudoeurycea and Chiropterotriton. Antisera Species tested B R C L S CB CM P. bellii (B) 0 39 74 52 43 84 88 P. brunnata (R) 53 0 72 48 15 67 77 P. cephalica (C) 78 49 0 64 62 90 107 P. leprosa (L) 72 53 88 0 35 92 88 P. smithi (S) 47 21 71 35 0 60 87 C. bromeliacia (CB) 79 53 90 92 71 0 104 C. multidentatus (CM) 88 66 100 57 87 98 0 complete adjuvant and albumin (1.2:1). min available. Despite the relatively low Three weeks later, 1 cm3 of albumin titers, the antisera exhibited standard be- solution was administered intravenously havior, with an average slope for all sev- in the marginal ear-vein; this was re- en antisera of 385, similar to slopes re- peated one week later. The rabbit was ported by other workers for mammali- bled from the marginal ear-vein or by an, anuran, and salamander albumins heart puncture one week after the sec- (Champion et al., 1974; Larson et al., ond intravenous injection. A total of 2-3 1981; Maxson et al., 1979). mg of albumin was administered per rab- MC'F tests were conducted in all pair- bit over the total period. Three rabbits wise combinations and the averages of were used for each immunogen, and in- these reciprocal tests are shown in Table dividual antisera were tested for purity 3. The percent standard deviation from by the criteria described by Wallace et al.