3种青蟹线粒体12S rRNA基因序列分析

对采自泰国、马达加斯加和日本各地的青蟹属的3种青蟹Scylla serrata(Forskal)、S．oceanica(Dana)和S．tranquebarica(Fabricius)的线粒体12S rRNA基因片段序列进行了测定，分析研究了其种间遗传差异及系统发育关系。研究结果显示：S．serrata、S．oceanica及S．tranquebarica在12SrRNA基因片段上存在长度差异，3种青蟹的序列长度分别为422bp、426bp、425bp；种内个体间无序列差异或差异极小，种间序列差异远大于种内差异。以日本鲟和底栖短桨蟹为外群，采用距离法和最大简约法重新构建了3种青蟹的分子系统树，得到的三个明显的分枝分别对应于上述3种青蟹，S．oceanica与S．tranquebarica两种间的亲缘关系较近。研究结果支持3种青蟹为不同物种的观点，建议对其进行分别的渔业管理。

Sequence analysis of mitochondrial 12S rRNA gene in three species of Scylla

This paper deals with the sequence analysis of mitochondrial 12S rRNA gene fragment and phylogenetic relationship of three mud crabs , Scylla serrata (Forsk l) , S . oceanica (Dana) and S. tranquebarica (Fabricius) collected from Japan , Thailand and . Madagascar. The result indicated that there was length variation among three mud crabs , which was 422bp , 426 bp and 425 bp respectively. Genetic distance inter2species was greater than that intra2species. Trees constructed by distance method and maximum parsimony method using Charybdis japonica and Thalamita prymna as the outgroup indicated that there were three distinct clades corresponding to S . serrata , S . oceanica and S . tranquebarica respectively. It suggested that the three mud crabs should be recognized as valid species and managed as different fishery management unit.