Investigation of genetic diversity in wild colonies of naked mole-rats (Heterocephalus glaber) by DNA fingerprinting

DNA from 20 individuals from four wild colonies of naked mole-rats, Heterocephalus glaber , were analysed for restriction fragment length polymorphism of class I major histocompatibility complex genes and minisatellite DNA, both of which have been shown to be highly variable between individuals in other species. The minisatellite probe employed in this study revealed limited polymorphism in the DNA of naked mole-rats, both within and between neighbouring colonies. Of the two class I major histocompatibility complex probes, both showed a lack of polymorphism within colonies, while one revealed a single difference in the restriction fragment pattern between one colony and the other three. This probe also revealed a possible variation in copy number of genes in some individuals. The low numbers of bands on the restriction fragment pattern also indicated that the naked mole-rat MHC I, in contrast to that of other mammalian species, may contain relatively few genes homologous to the class I major histocompatibility complex of the mouse. The absence of variability in naked mole-rat DNA in these normally highly polymorphic loci suggests that there may be little or no genetic diversity either within or between closely neighbouring colonies of naked mole-rats in the wild. The lack of polymorphism in the MHC I questions its possible role in individual odour recognition in this species of rodent.