Phylogeography of the Japanese White-Toothed Shrew (Eulipotyphla: Soricidae): A Clear Division of Haplogroups between Eastern and Western Japan and their Recent Introduction to Some Regions

Abstract

The Japanese white-toothed shrew (Crocidura dsinezumi) is a species endemic to Japan. For this species, only minimal phylogeographic investigations have been conducted. We obtained DNA sequences of mitochondrial cytochrome b and control region and nuclear ApoB genes for 191 individuals of C. dsinezumi from 107 locations collected throughout its known range. In the phylogenetic trees based on mitochondrial DNA sequences, two haplogroups (Eastern and Western Clades) were recognized, and the demarcation line between them was located in central Honshu without an overlapping area. The estimated divergence time between the two major clades indicated that they could have diverged prior to the final geologic division of Hondo and the Asian Continent (100–150 KYA). For the ApoB gene, Types A, G, and R (heterozygote) were recognized although there was a single site mutation. Type A mainly occurs in eastern and central Japan and Types G and R in central and western Japan. It was suggested in the present study that some shrews in Hokkaido were introduced recently from eastern Honshu (possibly the Tohoku Region) whereas others might have been distributed there naturally, and that population in Jeju (South Korea) was introduced recently from Kyushu.