Molecular phylogeny of red-backed voles in Far East Asia based on variation in ribosomal and mitochondrial DNA

Phylogenetic relationships among various species of red-backed voles (Cleth rionomys and Eothenomys) from areas surrounding the Sea of Japan were asses sed by examining variation in the nuclear ribosomal DNA (rDNA) and mitochon drial DNA (mtDNA). The rDNA data indicated at least six phylogenetically di stinct lineages represented by C. rufocanus, C. rex, C. rutilus, E. anderso ni, E. smithii, and E, melanogaster. Lineages of rufocanus-rex and anderson i-smithii can be regarded as sister species, respectively. The mtDNA data g enerally were congruent but also suggested the splitting of two additional species lineages, C. regulus from C. rufocanus and E. imaizumii from E. and ersoni-smithii. Our data revealed that these species have a complex evoluti onary history, which includes interspecific gene flow.