Intrageneric diversity of the cytochrome b gene and phylogeny of Eurasian species of the genus Mustela (Mustelidae, Carnivora)

To illuminate molecular phylogenetic relationships among Eurasian species o f the genus Mustela (Mustelidae, Carnivora), we determined nucleotide seque nces of the complete mitochondrial cytochrome b gene region (1,140 base pai rs). Molecular phylogenetic trees, constructed using the neighbor-joining a nd the maximum likelihood methods, showed the common topology of species re lationships to each other. The American mink M. vison first branched off an d was positioned very remotely from the other species of Mustela. Excluding M. vison, the ermine M. erminea first split from the rest of the species. Two small body-sized weasels, the least weasel M. nivalis and the mountain weasel M, altaica, comprised one cluster (named "the small weasel group"). The other species formed another cluster, where the remarkably close relati onships among the domestic ferret M. furo, the European polecat M. putorius , and the steppe polecat nn. eversmanni were noticed with 87-94% bootstrap values (named "the ferret group"), supporting the history that the ferret w as domesticated from IM. putorius and/or M. eversmanni The European mink M. lutreola was the closest to the ferret group. The genetic distance between the Siberian weasel M. sibirica and the Japanese weasel M. itatsi correspo nded to differences of interspecific level, while the two species were rela tively close to M. lutreola and the ferret group. These results provide inv aluable insight for understanding the evolution of Mustela as well as for i nvestigating the hybridization status between native and introduced species for conservation.