Suzuki H, Minato S, Sakurai S, Tsuchiya K, Fokin I M
Division of Bioscience, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan.
Zoolog Sci. 1997 Feb;14(1):167-73. doi: 10.2108/zsj.14.167.
The Japanese dormouse, Glirulus Japonicus, is the only extant lineage that represents this genus and it has been classified as a single species distributed on the three main islands of Japan, namely Honshu, Shikoku and Kyushu. However, individuals collected from Fukui, Wakayama and Kochi Prefectures (southwestern part of Japan) yielded distinctly different profiles of restriction fragments of the nuclear ribosomal DNA (rDNA) spacer from those collected from Yamanashi and Nagano Prefectures (central Japan). The estimated sequence divergence between the two groups was 2.8% on average, which corresponds to a putative divergence some two million years ago. Representing mitochondrial DNA (mtDNA) sequences, 402 bases of cytochrome b gene were determined by direct sequencing and the estimated extent of the sequence divergence between the two groups was 6.5-7%. Differences between the two geographic groups were also substantial in the sequences of about 300 base-fragments from the Y-linked, sex-determining locus, Sry. To assess the phylogenetic relationships between the Japanese dormouse and members of the family Myoxidae, we compared sequences of mitochondrial 12S rRNA gene of Japanese dormice with those of the forest dormouse (Dryomys nitedula) and the common dormouse (Muscardinus avellanarins), two continental genera thought to be closely related to the genus Glirulus. The results showed that the sequences from Japanese dormice were distinct from any sequences of the two continental species and the extent of the differences were somewhat similar to that between the rat (Rattus norvegicus) and the hamster (mesocricetus auratus).
日本睡鼠（Glirulus Japonicus）是该属现存的唯一谱系，它被归类为分布在日本三个主要岛屿（本州、四国和九州）的单一物种。然而，从福井、和歌山和高知县（日本西南部）采集的个体，其核糖体DNA（rDNA）间隔区的限制性片段图谱与从山梨县和长野县（日本中部）采集的个体明显不同。两组之间估计的序列差异平均为2.8%，这相当于大约两百万年前的假定分歧。作为线粒体DNA（mtDNA）序列的代表，通过直接测序确定了细胞色素b基因的402个碱基，两组之间估计的序列差异程度为6.5 - 7%。在来自Y连锁性别决定基因座Sry的约300个碱基片段的序列中，两个地理群体之间的差异也很大。为了评估日本睡鼠与睡鼠科成员之间的系统发育关系，我们将日本睡鼠的线粒体12S rRNA基因序列与森林睡鼠（Dryomys nitedula）和普通睡鼠（Muscardinus avellanarins）的序列进行了比较，这两个大陆属被认为与Glirulus属密切相关。结果表明，日本睡鼠的序列与这两个大陆物种的任何序列都不同，差异程度与大鼠（Rattus norvegicus）和仓鼠（Mesocricetus auratus）之间的差异有些相似。
