Genetic relationships Within and between the Japanese marten Martes melampus and the Sable M. zibellina, based on variation of mitochondrial DNA and nuclear ribosomal DNA

We examined the intra- and inter-specific genetic relationships of the Japanese marten Martes melampus and the sable M. zibellina using cytoplasmic and nuclear DNA markers. The interspecific sequence divergences in the 402 base pairs of the mitochondrial cytochrome b gene averaged 3.3%. The extent of the divergences among thirteen individuals of M. melampus collected from Honshu, Shikoku, Kyushu and Tsushima was small (≤0.5%), irrespective of their fur color variation. A somewhat higher degree of intra-specific variation (up to 1.3%) was observed among M. zibellina specimens, but the extent of inter-populational variation between Primorye, Russia, and Hokkaido, Japan, was not so high (minimum 0.2%), suggesting that there has been recent genetic communication between Hokkaido and the continent. Among the 24 restriction sites of the nuclear ribosomal DNA spacer, there was no difference within either species, however one site differed between the two species. Using these molecular markers we confirmed that an amimal from Hokkaido, showing the typical morphological characteristics of M. melampus, possessed the same genotype as M. melampus from Honshu. From these results and descriptions in the literature, we presumed that the animal in question could be a descendent of M. melampus introduced to Hokkaido from Honshu by fur farmers about 50 years earlier. Eight animals examined from Hokkaido showed no indication of hybridization between the two species.