基于COI基因分析的双齿蚋分子分类研究

Study on Molecular Classification of Simulium bidentatum Based on Mitochondrial COI Gene

为了确定COI基因序列分析在蚋科中的分类地位,本研究测定了双齿蚋(Simulium bidentatum) COI基因序列,分析该基因序列特征;下载与其同源性较高的12个蚋种的COI基因序列15条,进行同源性分析和分子系统发育研究。结果显示,双齿蚋COI基因序列(DQ534946)与S. notiale、S. snowi、S. nyssa等蚋种的COI基因序列同源性最高,在贝叶斯分析所构建的分子系统进化树中,不同蚋组的序列各自聚成一枝,双齿蚋序列(DQ534946)未与其他任何蚋种聚为一枝。研究结果表明,双齿蚋COI基因序列与蚋亚属序列同源性较高,COI基因序列分析能较好建立蚋亚属内组间关系,双齿蚋未与其他蚋组序列聚为一枝,分类至淡足蚋组并不合适,支持分类至阿根蚋组。本研究进一步明确了COI基因序列分析在蚋科分子系统发育研究中的意义,并在一定程度上解决了双齿蚋在蚋科的分类争议。

In order to determine its taxonomic status of Simulium bidentatum in the family by the analysis of COI gene sequence of Simulium bidentatum, the homology and molecular phylogeny for one COI gene sequence of S.bidentatum determined and 15 COI gene sequences of 12 species downloaded from the GenBank were analyzed in this research. Research results showed that COI gene sequence of S. bidentatum and S. notiale, S. snowi, S. nyssa have the highest homology. In the phylogenetic tree based on COI gene, the sequences of the different Simulium groups formed a clade respectively, and the sequence of S. bidentatum(DQ534946) didn’t form a clade with any other groups sequences. In conclusion, these results suggested that COI gene sequence of S. bidentatum and Simulium subgenus sequences have higher homology and COI gene could better discriminate Simulium subgenus at the group level. It was more accurate to class S. bidentatum into argentipes group instead of malyschevi group because S. bidentatum wasn’t formed a robust clade with malyschevi group. This study further clarified the significance of COI gene sequence in the molecular Phylogeny of Simuliidae, and solved the classification status of S. bidentatum in a certain extent.