基于线粒体COI基因序列进行库蠓二囊亚属近似种的分子鉴定

Molecular identification of the genus Culicoides(Avaritiais)(Diptera:Ceratopogonidae) based on the mtDNA-COI gene

目的通过采用线粒体COI基因进行库蠓近似种分子鉴定的方法,来弥补传统形态学在种类鉴定中存在的操作繁琐、难度大等不足,从而实现库蠓近似种的快速、准确鉴别。方法采用DNA测序的方法获得库蠓属二囊亚属的林岛库蠓(C.gaponus)、标翅库蠓(C.insignipennis)、无害库蠓(C.innoxius)、连斑库蠓(C.jacobsoni)、南山库蠓(C.lansangensis)、新竹库蠓(C.liui)、长喙库蠓(C.longirostris)、异域库蠓(C.peregrinus)等8种库蠓近似种的部分线粒体COI序列,并对其进行分子鉴定;基于Kimura 2-parameter模型分析遗传距离,同时应用MEGA 6.0软件以荒川库蠓C.arakawai为外群构建系统发育树。结果 8种库蠓COI序列长度约650bp;遗传距离在种内和种间具有统计学差异(t=119.452,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。结论本研究证实了线粒体COI序列可用于进行库蠓近似种的分子鉴定。

The aim of this study is to differentiate sibling species of blood-sucking midges rapidly and accurately and make up for the deficiency of complex operation and big difficulty effectively in the traditional morphological species identification. The sequences of eight closely related species of the genus Culicoides, C. gaponus, C. insignipennis, C. innoxius, C. jacobsoni, C. lansangensis, C. liui, C. longirostris and C. peregrinus, were obtained by DNA sequencing based on mitochondrial cytochrome c oxidase subunit I gene （mt-COI）. Approximately 650 bp of COI gene were sequenced for those 8 species. The genetic distances results of COI gene which were based on Kimura 2-parameter model showed that intraspecific genetic distances was different from that of interspecies significantly （t=119.452,P〈0.05）. The phylogenetic relationship within Culicoides which take the C. arakawai as outgroup indicated 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 as well as these results were consistent with those of morphological taxonomy. All the results lead to a conclusion that the mitochondrial cytochrome c oxidase subunit I gene can be used as the molecular identification for sibling species of blood-sucking midges.