基于线粒体COI基因的DNA条形码在光唇鱼属鱼类系统分类中的应用

Application of DNA barcoding based on mitochondrial COI gene in the phylogenetic classification of Acrossocheilus

本文基于COI基因序列对光唇鱼属13种鱼类进行分子鉴定及系统进化研究。结果表明,光唇鱼属各物种间遗传距离,除了北江光唇鱼(A.beijiangensis)与窄条光唇鱼(A.stenotaeniatus)之间的遗传距离(0.0157)外,其余物种间遗传距离都大于0.0200。在分子系统发育树上,北江光唇鱼与窄条光唇鱼形成一个分支,且因其种间遗传距离达不到种的划分水平,结合已有的资料判断两者可能为同一物种;吉首光唇鱼(A.jishouensis)在分子系统发育树上与侧条光唇鱼(A.parallens)和半刺光唇鱼(A.hemispinus)聚为姐妹分支,且与两者的种间遗传距离都明显大于0.0200,吉首光唇鱼应为一个有效种;半刺光唇鱼和带半刺光唇鱼(A.cinctus)在系统树上各自分布在2个独立的分支上,且两者间遗传距离比各自与同分支上的物种间遗传距离大,故判断它们的差异已达到种的水平。本研究结果表明线粒体COI基因序列能有效地对光唇鱼属鱼类进行物种鉴定,并可用于探讨光唇鱼属的系统发育研究。

Based on the COI gene sequence,13 species of Acrossocheilus were analysed.The results showed that the genetic distance between species of Acrossocheilus is more than 0.0200 except for the genetic distance between A.beijiangensis and A.stenotaeniatus(0.0157).In the phylogenetic tree,A.beijiangensis and A.stenotaeniatus formed as the same clade,which genetic distance less than the level of species classification.The two species may be the same species with two different names.The genetic distance from A.jishouensis,A.parallens and A.hemispinus protrudated into sister branches in phylogenetic tree,and the genetic distance from both was obviously greater than 0.0200,which showed that A.jishouensis is an effective specie.A.hemispinus and A.cinctus were distributed in two independent branches of the phylogenetic tree,and the genetic distance between them is larger than that between the species on the same branch,so they should be regarded as two separate species.The results of this study indicate that mitochondrial COI gene sequences are effective for species identification and can be used to explore the phylogeny of Acrossocheilus.