Naked Mole Rats (Heterocephalus glaber): Examining the Effects of Bottlenecks and Geographic Barriers on the Genetic Structure of Colonies
| Previous studies of eusocial naked mole-rats (Heterocephalus glaber) in southern Kenya have suggested a low level of gentiec diversity within colonies as well as between colonies (Reeve et al, 1990; Faulkes et al,1997). Braude (2000) questioned the sampling techniques that these studies used, especially since most colonies sampled were from the same locality. By including colonies from more distant locales, we tried to test Braude’s bottleneck hypothesis for why naked mole-rat populations in the Mtito Andei region have exhibited such low genetic variation. Using microsatellite loci designed for H. glaber as well as for two closely related species, Cryptomys mechowi and Georychus capensis, we assessed genetic variation, using the polymerase chain reaction and automated genotyping, among populations of H. glaber distributed throughout southern Kenya. Thus far, these genetic data indicate a high level of divergence among major geographic localities as well as high genetic subdivision among colonies on a microgeographic scale, possibly as a consequence of the high level of social structure displayed by this species. In addition, the Mtito Andei populations reveal considerably less heterozygosity at specific loci than seen at other localities that presumably did not experience a population bottleneck. This observation is congruent with Braude's hypothesis of a local bottleneck for the Mtito Andei populations. |
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