Mitochondrial DNA variation and the evolutionary history of chromosome races of collared lemmings (Dicrostonyx) in the Eurasian Arctic

摘要: Collared lemmings (Dicrostonyx) demonstrate extensive chromosome variation along their circumpolar distribution in the high Arctic. To reveal history of this genus and origin races Palearctic, we studied geographical pattern mtDNA from 13 localities by using eight tetranucleotide restriction enzymes. The main split phylogeny is at Bering Strait corresponds to division between Beringian Eurasian groups karyotypes. Nucleotide divergence estimate 6.8% suggests that, despite Land Bridge, Palearctic Nearctic forms have been separated since mid-Pleistocene. Five distinct phylogenetic haplotypes, with average 1.5%, corresponding regions, were found coast. Low nucleotide haplotype diversity a star-like within phylogeographical haplotypes suggest regional bottleneck events recent past, most probably due warming during Holocene. There congruence races; 69% total allocated among races. This implies that historical such as fragmentation allopatric important for However, factors do not explain fixed autosome fusions distinguish certain populations.