Genetics of Captive Naked Mole-Rat Populations

Abstract

The evolution of highly social behavior (eusociality) represents one of the major transition points in evolutionary history. Naked mole-rats (NMRs), Heterocephalus glaber, are one of the few known eusocial mammals, meaning that they have a social caste system with a reproductive division of labor. In addition, NMRs show remarkable aging properties and tolerance to pain. Thus NMRs are important systems for studying life history traits. Surprisingly, however, very little is known about the mating systems and habits of NMRs. The goal of this study is to gain a better understanding of the population genetics and breeding habits of NMRs by creating a method for determining variation at microsatellite marker regions. Microsatellites are highly variable regions of the genome, which can act as identifiable markers for individuals. We have collaborated with Zoo Atlanta to study the population genetics of NMRs. We developed primer sets for examining variation at 54 microsatellite locations. Each of these loci were studied with up to 18 NMR individuals. We did this using traditional fluorescent primers and an M13-tailed fluorescent primer method that allows for cheaper and easier screening of samples. Six of these markers showed variability with two possible alleles. Thus, we have obtained the first estimates of genetic variation from the Zoo Atlanta NMR population. Our preliminary results also suggest that the population is in Hardy-Weinberg Equilibrium (HWE), which is unexpected because the population is not randomly mating. These methods and preliminary results provide insight into the breeding programs among captive NMR populations. In addition, the techniques developed will be useful for studying NMR biology in other contexts and help us understand the development of sociality and variation in health systems.