Abstract: In order to clarify the population phylogeographic relationship and subspecies differentiation of Sorex unguiculatus and Sorex gracillimus, this study analyzed the Cyt b gene sequences of S. unguiculatus (11 samples) and S. gracillimus (17 samples) collected from Northeast China together with Cyt b gene sequences of S. unguiculatus (32 samples) and S. gracillimus (22 samples) downloaded from GenBank. The different geographical populations of the two species showed different geographical patterns. In the phylogenetic tree of S. unguiculatus, there was no correlation between molecular system relation and geographical distribution. In the phylogenetic tree of S. gracillimus, samples from Northeast China were clustered into a separate clade apart from samples from Russia and Hokkaido, Japan. A similar geographical pattern was also observed in the Median-joining network analysis. Neutral tests supported S. unguiculatus has experienced population expansions in the recent past, but S. gracillimus has not experienced dramatic population expansions. The results also supported that S. unguiculatus has no subspecies differentiation. On the other hand, we found that S. gracillimus was divided into two subspecies across the geographic area of this study, one subspecies distributed in Northeast China and the other subspecies distributed in the Russian Far East (from southern Magadan to Primorsky Krai, Sakhalin Island included) and Hokkaido, Japan.

Key words: Sorex, Molecular phylogeography, Subspecies diversification

摘要： 为明确长爪鼩鼱(Sorex unguiculatus)和细鼩鼱(Sorex gracillimus)的种群系统地理关系以及亚种分化，本文测定了我国东北地区长爪鼩鼱11个样本和细鼩鼱17个样本的Cyt b基因序列，并结合GenBank下载32个长爪鼩鼱和22个细鼩鼱的Cyt b基因序列进行整合分析。两个物种不同地理种群表现出不同的地理分化格局：长爪鼩鼱系统进化树结果显示，其分子系统关系与地理分布无相关性；细鼩鼱系统进化树结果显示，中国东北的样本聚为一个独立的进化支，俄罗斯的样本和日本北海道的样本聚为一个进化支。中介网络分析也观察到相似分化格局。中性检验支持长爪鼩鼱在近期可能发生过种群扩张，而细鼩鼱未经历过数量急剧扩张。上述结果支持长爪鼩鼱无亚种分化，细鼩鼱可能包含两个地理亚种，分别对应我国东北的地理种群以及俄罗斯远东(马加丹南部到滨海边疆区，包括萨哈林岛)和日本北海道的地理种群。

关键词: 鼩鼱属, 分子系统地理学, 亚种分化