An Electroporetic and Chromosomal Study of the Dasyurid Marsupial Genus Ningaui Archer

Abstract

Isozyme electrophoresis of 28 loci was used to characterize 30 specimens of Ningaui from four States of Australia. The specimens fall into three genetic groups, with large differences between groups (21-32% fixed differences) and genetic homogeneity within groups. One group, from the Pilbara of Western Australia, is referable to N. timealeyi; a second group, extending from the Kalgoorlie area of Western Australia to the far west of South Australia and north to the Tanami Desert of the Northern Temtory, is referable to N. ridei; and a third group extends from the Kalgoorlie area of Western Australia (where it is sympatric with N. ridei) across southern South Australia and into north-westem Victoria. Because the third group maintains its genetic uniqueness despite being sympatric with N. ridei, it clearly represents a different species, N. yvonnae Kitchener, Stoddart & Henry. This species is distinguishable from N. ridei on skull characters, but indistinguishable on external characters. In contrast to most dasyurids, ningauis display considerable karyotypic diversity involving a pericentric inversion, a reciprocal translocation and addition of constitutive heterochromatin to the X-chromosome.