两种体色三疣梭子蟹线粒体DNA 部分片段序列的比较分析

三疣梭子蟹(Portunus trituberculatus)作为重要的海洋经济动物,其常见体色(头胸甲)为茶绿色。近年来在我国沿海海域海捕三疣梭子蟹中开始出现体色为紫色的一类梭子蟹,除体色不同外,二者表型特征并无显著差异。对两种体色三疣梭子蟹不同个体的线粒体COI和16S rRNA基因进行了序列比对分析以判定二者之间的亲缘关系。结果发现COI和16S rRNA基因在两种体色三疣梭子蟹群体中的核苷酸序列一致性分别为99.87%和99.88%,表明紫色三疣梭子蟹并未发生亚种的分化,即紫色和茶绿色群体属于同一个种。并利用GenBank数据库检索了梭子蟹科其他15种海产蟹的16S rRNA序列,进行了序列同源性比对分析和分子系统学方面的探讨,为梭子蟹种属分类学研究提供分子依据。

Comparison analysis between purple and tea-green individuals of Portunus trituberculatus using mitochondrial partial genes

The blue swimming crabs, an important commercial species, with different body-colors were discovered along the coast of East China in recent years. Both purple and tea-green crabs have similar, even the same physical characteristics except for the carapace color. In order to identify the relationships between them, we amplified and compared two conserved mitochondrial gene fragments of color-different crabs through DNA sequencing analyses. The sequence alignment analysis of color-different crabs presented 99.87% and 99.88% nucleotide sequence identity for the COI and 16S rRNA genes, respectively, indicating that there was no species or subspecies differentiation between them. Based on the alignment of nucleotide sequences, a phylogenetic tree of 16S rRNA genes from 16 species of Portunidae was constructed. It may serve as a basis for the taxonomy of portunid crabs.