Estimating the Extent of Biochemical Genetic Variation in Eight Species of the Felidae

Abstract

The disparity in the level of genetic variation detected in the domestic cat and the cheetah provokes questions concerning the heterozygosity of other felid species. Eight other felids were examined using standard isozyme electrophoretic techniques, including representatives of the small cats, the large cats (Panthera), and felids of intermediate size. The ocelot was determined to have levels of genetic variation comparable to the domestic cat, while the margay, caracal, serval, lion, leopard, tiger, and clouded leopard have intermediate levels of variation. The cheetah is established as an unusual felid in its degree of monomorphism. Comparisons of patterns of polymorphism revealed a tendency for certain loci to be more variable than others. A group of other loci are monomorphic in the ten cat species which have been studied, and some of these are also unchanged in mobility between species. This implies that there are constraints imposed on the products of these genes which prevent variants from accumulating in the population. Intra- and interspecific comparisons have also shown that two subspecies of the tiger may be discriminated on the basis of genetic variation and that the various felid species differ in electrophoretic mobility at a number of isozyme loci, making comparative isozyme studies of use in elucidating the phylogeny of the family Felidae.