Determination of genetic diversity and distribution of two Anatolian endemics voles (Microtus anatolicus & M. dogramacii)

Identification of biogeographic patterns are important for promoting conservation plans and understanding the evolutionary history of refugial endemic species. In this study, we aim to determine the genetic diversity and geographic range of two Anatolian endemic vole species, M. anatolicus and M. dogramacii. Both voles species are classified under the Socialis group. Social voles consist of ten widespread species from the Balkans to the Middle East. Phylogenetic studies on social voles display high level cryptic species diversity. However, the knowledge about the geographic range and population structure of their species within Anatolia is still unclear. In order to determine the distribution range of target species, we sampled 137 localities throughout Anatolia. We also obtained Microtus samples from seven localities from Iran. Finally, we sequenced the mitochondrial CYTB gene of 253 individuals throughout Anatolia and Iran from 87 localities and utilized them together with 103 GenBank sequences. In addition to CYTB sequences, two nuclear exon regions and seven polymorphic microsatellite markers are added to mtDNA data set. We showed that M. anatolicus is a narrow distributed clade, restricted to Central Anatolian steppes. Anatolian voles were collected from Aksaray, Antalya, Karaman, Konya and Nigde Province. We identified 10 mtDNA haplotypes for M. anatolicus, seven haplotypes for the first time in this study. The genetic diversity of Anatolian vole populations is low in parallel with its narrow distribution (Hd=0.809) when compared with the other mtDNA clades in Socialis group. The TCS network that obtained from mtDNA data shows the presence of two subpopulations of M. anatolicus which has weak population structure. In the Taurus Mountains, we found M. anatolicus and M. irani populations in sympatry. Microtus dogramacii has a wide range of distribution. The distribution regions of M. dogramacii are in North-central Anatolia, East Anatolia, Jordan and North Iran. It is separated to two subpopulations as Anatolia - Jordan and East Anatolia - Iran. The genetic diversity of M. dogramacii is higher than other species in the Guentheri group (Hd=0.914). In total, we observed 18 mtDNA haplotypes (seven of which is new), belonging to 33 samples for M. dogramacii. The distribution area of M. dogramacii in Anatolia is largely sympatric with M. hartingi which is defined in the same species group. The data can be concluded as four major results. Firstly, Microtus anatolicus ve M. dogramacii form two well-supported phylogeographic groups due to mtDNA data set. Secondly, we assigned that M. dogramacii and M. qazvinensis are the same species. In this case, M. dogramacii is not a Turkish endemic mammal species. Thirdly, we defined mitonuclear discordance among Socialis species group. Microtus anatolicus and M. irani were classified as separate species in regard to mitochondiral data, however microsattelite markers indicate that there are no reproduction barrier between these sympatric populations at Taurus and both species hybridize between their populations. Similarly, the nuclear exons demonstrated that some haplotypes are shared between these two clades. For these reason, M. anatolicus and M. irani were classified as two subspecies of same species. In conclusion, none of the Anatolian populations seem belong to M. socialis genetically. These results show the taxonomic status of M. anatolicus and M. dogramacii should be changed since they are not Anatolian endemics. Even though social voles are classified as separate species in regard to mitochondrial data, nuclear markers indicate that they are more likely to be affected by incomplete lineage sorting or recent gene flow. This study highlighted that diversity patterns in vole populations support occurrence of refugial areas within Anatolia.