Natural hybridization between parthenogenetic and bisexual lizards: detection of uniparental source of skin grafting.

Skin graft evidence is used to directly identify the unisexual parent of natural hybrids produced between the bisexual species Cnemidophorus inornatus and the unisexual Cnemidophorus neomexicanus. Reciprocal grafts transplanted among there suspected hybrids between Cnemidophorus inornatus and Cnemidophorus neomexicanus are rejected as well as grafts from the hybrids to C. neomexicanus, indicating that the hybrids are each genetically different from each other and that C. neomexicanus has the ability to reject foreign grafts. Allografts among C. neomexicanus and xenografts from C. neomexicanus to the hybrids are not rejected, indicating that C. neomexicanus is genetically homogeneous and that the hybrids possess genomes genetically identical to C. neomexicanus. Electrophoretic analysis of the hybrids and their probable parents supports the evidence obtained from skin grafting that C. neomexicanus is one of the parents, and suggests that C. inornatus, rather than C. tigris, is the bisexual parent. Chromosome spreads obtained from the hybrids reveal a triploid number of 69, a number consistent with their presumed origin from unreduced diploid ova (2N = 46) from C. neomexicanus and haploid serum (N = 23) from C. inornatus. Preliminary evidence is presented of the first hybrids known between Cnemidophorus inornatus and Cnemidophorus uniparens. Histological examination of the tests suggests that these hybrids are sterile. Included is a list summarizing all known hybrids between bisexual and unisexual species of the genus Cnemidophorus.