Dec 13, 1990 - salamander, Phaeognathus hubrichti, were estimated by examination of variation in ..... lution of the lungless salamanders, family Pletho-. 5273 ...
Herpetologica, 47(4), 1991, 440-447 © 1991 by The Herpetologists' League, Inc.
PROTEIN AND MITOCHONDRIAL DNA VARIATION IN THE SALAMANDER PHAEOGNATHUS HUBRICHTI MARK L. MCKNIGHT, 1'3 C. KENNETH DODD, JR., 2 AND CHRISTINA M. SPOLSKY' 'Department of Ecology, Ethology and Evolution, University of Illinois, Urbana,IL 61801, USA 'National Ecology Research Center, U.S. Fish and Wildlife Service, Gainesville, FL 32601, USA ABSTRACT: The genetic diversity and spatial distribution of selected genes of the Red Hills salamander, Phaeognathushubrichti, were estimated by examination of variation in mitochondrial DNA (mtDNA) and proteins of 14 individuals collected across the entire range of the species. Digestion of mtDNA with each of 22 restriction enzymes resulted in fragment patterns that did not vary among these individuals. Nine of 35 protein loci were polymorphic; four of these showed a geographic pattern to the variation and suggest the existence of two forms in this threatened species. Preserves to protect the genetic diversity of this animal should include areas representing both forms. Key words: Caudata; Phaeognathus hubrichti; Genetics; Endangered species; Conservation; Genetic diversity
DURING the 15 yr following the description of the Red Hills salamander, Phaeognathus hubrichti Highton (1961), most research activity focused on the species' morphology (Brandon, 1965; Highton, 1961; Valentine, 1963b), distribution, ecology, and natural history (Brandon, 1965, 1966; Jordan, 1975; Schwaner and Mount, 1970; Valentine, 1963a), and population status (French and Mount, 1978; Jordan and Mount, 1975). The unique life history characteristics, limited distribution, and restricted habitat requirements of this salamander, in conjunction with the rapid destruction of its habitat through clearcutting and mechanical site preparation, led to its determination as a threatened
phology, it is thought to belong within the Desmognathinae (Highton, 1961; Wake, 1966). We examined the genetic structure of P. hubrichtias revealed by restriction fragment length polymorphisms of mitochondrial DNA (mtDNA) and starch gel electrophoresis of proteins. Using both the clonally inherited, maternally transmitted mtDNA and the sexually transmitted, recombining genes for allozyme characters, we describe the current population genetic structure of P. hubrichti and suggest possible historical factors that could have resuited in the present distribution of genetic variation.
species under U.S. federal law (U.S. Fish
MATERIALS AND METHODS
and Wildlife Service, 1976). Recently a recovery plan (U.S. Fish and Wildlife Service, 1983) and a review of its status after 12 yr of protection (Dodd, 1990, 1991) have been published. Little is known regarding such basic biological attributes of this species as its population genetic structure or its systematic position within the Plethodontidae, although, based on mor-
Fourteen specimens of P. hubrichti, from 13 localities across the range of the species, were used in this study (localities A-M: Fig. 1, Table 1). Two specimens were available from locality H; all other localities were represented by single specimens. We isolated mtDNA from livers, hearts, and ova (if available) of each specimen using a modification of Spolsky and Uzzell's (1984, 1986) method (Mack et al.,
PRESENT ADDRESS: Department of Zoology, Uni-
1986). We used 22 type II restriction en-
versity of California at Davis, Davis, CA 95616, USA.
donucleases to digest each mtDNA (Table
3
440
I
I
441
HERPETOLOGICA
December 1991]
_._.._._ u
Big ^\\-^
