Population Genetic Structure of Transcaucasian Mole Vole (Ellobius lutescens) Along Zagros Mountains, Iran

Abstract

The Zagros and Alborz mountainous ridges can be regarded as one of the most interesting and known physical barriers responsible for the vicariance event. Based on the probable effect of Zagros Mountains on the rodent population vicariance, a research on Caucasian mole vole phylogeography, population genetic structure and diversity was designed along the mentioned mountainous areas. To this end, a total of 38 tissue samples were collected from the northern parts of the study area to the southern parts. Obtained mitochondrial cytb (1041 bp) sequences were used in this phylogenetic analysis. The phylogenetic analysis was based on the TRN+I evolutionary model and gaining Bayesian phylogenetic tree with maximum verification. By using median joining logic, the relationships between different acquired haplotypes were analyzed. It was shown that the Caucasian mole vole population had been disjointed (based on posterior probability of 1 and 100 bootstraps) along the Zagros mountainous ridges, especially in both geographical extremes located in the northern and southern parts of the mountainous ridges. Meanwhile from the 38 analyzed sequences, 17 haplotypes were obtained, of which 10 haplotypes were unique. The mutational steps between haplotypes were assessed by generating statistical parsimony haplotype networks, which yielded 36 mutational steps between the northern and southern populations. Based on neutrality tests and analyzing their power under sudden population expansions, it was found that this event happened around the northern and southern populations. Genetic distance of two percent between the northern and southern populations indicated the existence of local adaptations by these two groups, which can be regarded as evolutionary units.