基于线粒体COⅠ基因序列的吸血蠓近似种鉴定

Molecular identification of genus Culicoides( Diptera: Ceratopogonidae) based on mtDNA CO Ⅰ gene

为了快速、准确地鉴别吸血蠓近似种,弥补传统形态学鉴定方法在种类鉴定中存在的操作繁琐、难度大等不足,提出了基于线粒体COⅠ基因序列的吸血蠓近似种鉴定方法。以二囊亚属中的黑色库蠓(Culicoides pelius)、无害库蠓(Culicoides innoxius)、白带库蠓(Culicoides albifascia)、不显库蠓(Culicoides obsoletus)、东方库蠓(Culicoides orientalis)、苏格兰库蠓(Culicoides scoticus)和琉球库蠓(Culicoides actoni)等7种库蠓近似种的部分线粒体COⅠ基因序列作为分析对象,基于Kimura 2-parameter模型分析遗传距离,同时应用MEGA6. 0软件以荒川库蠓(Culicoides arakawai)为外群构建系统发育树(邻接法和最大似然法)。经过Clustal X序列比对及人工校对、编辑后,7种吸血蠓COⅠ基因长度为494 bp,遗传距离在种内和种间具显著差异(P <0. 05),系统发育树中不同库蠓种类各自构成单系(群),同种类不同地理种群聚为一支。本研究初步证实了线粒体COⅠ基因序列可用于吸血蠓近似种的分子鉴定。

In order to make up for the deficiency of complex operation and big difficulty effectively in the traditional morphological species identification of sibling species of blood-sucking midges and differentiate these rapidly and accurately,molecular identification of seven closely related species of the genus Culicoides,C.pelius,C.innoxius,C.albifascia,C.obsoletus,C.orientalis,C.scoticus and C.actoni were studied based on mitochondrial cytochrome c oxidase subunit I gene(COⅠ).Approximately 493 bp of COⅠgene were sequenced for those 7 species.Estimate genetic distances of COⅠgene,and statistical analysis showed that intraspecific genetic distances were different from that of interspecies significantly(P<0.05).The phylogenetic relationship within Culicoides indicates that the topologies of all the phylogenetic trees were quite similar.Distinguished between different species of Culicoides clearly,no cross between different species.The same species gathered closely with each other.These results were consistent with those of morphological taxonomy.