多毛类18S rDNA和COⅠ基因序列片段及其分子系统发育研究

Phylogenetic analysis of polychaetes based on sequences of 18S rDNA and COⅠsegments

应用分子系统发育学的方法,以多毛类18S rDNA和线粒体细胞色素C氧化酶亚单位Ⅰ(COⅠ)基因序列片段为分子标记,结合形态学特征对它们的分类地位进行了探讨.结果显示,四索沙蚕-梯斑海毛虫分枝的遗传距离为0.044,(四索沙蚕-梯斑海毛虫)-小头虫分枝的遗传距离为0.072,四索沙蚕分枝与岩虫分枝的遗传距离比较大,为0.091.分析结果显示18S系统发育树将仙女虫科定位为矶沙蚕目的内群分类单元,100%的Bootstrap值进一步表明仙女虫科和索沙蚕科的姐妹群关系;分析结果还显示了小头虫目与矶沙蚕目的亲缘关系密切.

Combining the morphological characters, five species of polychaetes were assessed for their phylogenetic position in parsimony analyses of 1 800bp from 18S rDNA and 709bp from CO Ⅰ. The results show that the genetic distance between Lumbrineris tetraura and Chloeia parva is 0. 044, Lumbrineris tetraura-Chloeia parva and Capitella capitata is 0. 057, Lumbrineris tetraura and Marphysa sanguinea is 0. 091, which means Amphinomidae is a ingroup taxon of Eunicida. Furthermore, the results indicate a sistergroup relationship between Amphinomidae and Lumbrineriiae, and a close relationship between Capitellida and Eunicida.