Mitochondrial DNA polymorphisms in subterranean mole-rats of the Spalax ehrenbergi superspecies in Israel, and its peripheral isolates

Patterns of mitochondrial DNA (mtDNA) variation were examined in 133mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n =58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as wellas the peripheral isolates of 2n = 60. In the main range of the complex, atotal of 28 mtDNA haplotypes were found in 64 mole-rats, with mosthaplotypes being unique to either a single chromosomal species orpopulation. mtDNA divergence increased from low to high diploid number in anorth-to-south direction in Israel. Overall levels of mtDNA diversity wereunexpectedly the highest in the 2n = 60, the youngest species of thecomplex. The mtDNA haplotypes can be separated into two major groups, 2n =52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealedevidence of a few haplotypes not sorted by diploid number. The overallpatterns of mtDNA divergence seen within and among the four chromosomalspecies are consistent with the parapatric mode of speciation as suggestedfrom previous studies of allozyme and DNA hybridization. In a separate dataset the patterns of mtDNA variation were examined across the maingeographic range and across peripheral semi-isolates and isolates of the 2n= 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats.High levels of mtDNA diversity characterized the main range, semi-isolated,and even some desert isolated populations. The peripheral isolates containmuch mtDNA diversity, including novel haplotypes.