Microsatellite diversity in populations of blind subterranean mole rats (Spalax ehrenbergi superspecies) in Israel: Speciation and adaptation

The genetic diversity, structure, and relationships of 12 populations of blind subterranean mole rats belonging to four species of the Spalax ehrenbergi superspecies were examined. Diversity levels and divergence of 19 nuclear microsatellite markers were analysed. Results indicate that the 12 populations fall into two major clusters representing the species pairs Spalax galili (2n = 52) and S. golani (2n = 54) vs. S. carmeli (2n = 58) and S.judaei (2n = 60). There is very little gene flow between the species pairs, except for one population (Afiq) of S. carmeli (2n = 58), which is located near the hybrid zone between S. golani (2n = 54) and S. carmeli (2n = 58). Higher values of the mean for alleles per locus, gene diversity, and number of unique alleles were observed for the southern species pair, S. carmeli and S.judaei, than for the northern species pair, S.galili and S.golani. Microsatellite diversity increases southward toward the Negev Desert and is positively correlated with aridity stress. Climatic factors of water availability coupled with temperature account for 76.7% of microsatellite variance. Natural selection appears to adaptively determine microsatellite evolution in Spalax regionally across Israel.