尖塘鳢属鱼类线粒体12SrRNA基因序列分析

Sequence analysis of mitochondrial 12S rRNA gene in Oxyleotris

利用PCR技术扩增和测序了线纹尖塘鳢、云斑尖塘鳢和海丰沙塘鳢线粒体12SrRNA基因,结合从GenBank中下载的部分同源序列,共分析了5种鱼类的系统发育关系。在Kimura2-parameter模型构建的邻接树中,原产泰国的云斑尖塘鳢与原产澳州线纹尖塘鳢均为单系类群,二者为亲缘关系最为密切的姐妹群,海丰沙塘鳢与其它群体的亲缘关系较远,支持将尖塘鳢属从塘鳢属中分出的传统分类处理。尖塘鳢属内云斑尖塘鳢和线纹尖塘鳢鱼类种内DNA序列无差异,而种间差异明显,表明线粒体12SrRNA基因可作为塘鳢科鱼类种类鉴定的良好分子标记。

Oxyeleotris lineolatus, O. marmoratus and Odontobutis haifengensis are highly priced freshwater fishes, yet interspecific relationships haven＇t been reported yet. In present study, partial mitochondrial 12S rRNA gene of these 3 species were sequenced. Combined with 5 homologous 12S rRNA gene from the GeneBank, eight sequences were analyzed. The pairwise genetic distances were computed by Kimura 2-pararneter model, and neighbor-joining based phylogenetic tree showed that Australia-originated O.lineolatus was a sister species to Tailand-endemic O.marmoratus. But Odontobutis haifengensis was distantly related to all other species, which is supporting the separation of Odontobutis from Eleotridae in traditional taxonomic treatment. Results showed that interspecific sequence divergence between O. lineolatus and O. marmoratus were obvious and no intraspecific 12s rRNA difference were observed, suggesting that mitochondrial 12S rRNA gene might be used as a useful molecular marker to identifv different species in Eleotridae.