基于16S rRNA与COI基因40种石斑鱼亚科鱼类分子系统进化关系

Molecular phylogenetic relationships of 40 species of Epinephelinae based on the partial sequences of 16S rRNA and COI genes

本研究采集了分布在西太平洋的石斑鱼亚科10属共40种鱼类,采用PCR扩增及测序技术获得所有样品16S rRNA、COI基因部分序列,利用最大似然法构建系统进化树并分析。结果表明:40种鱼类COI基因为651 bp,编码227个氨基酸,16S rRNA基因同源序列566 bp,序列存在一定的碱基插入与缺失,各物种16S rRNA基因序列变异比COI要少,序列较为保守。构建的系统进化树上,在本研究的石斑鱼亚科10个属中,鳃棘鲈属分类地位最原始,位于进化树基部,6种鳃棘鲈能聚成一个单系;烟鲈属与九棘鲈属关系较近,两者聚为一支,侧牙鲈属的进化地位介于鳃棘鲈属与九棘鲈属之间;石斑鱼属的进化地位最高,位于进化树顶部,形成两个平行分支,但是石斑鱼属种类未能聚成一个单系;驼背鲈属、鸢鮨属、下美鮨属、光腭鲈属及宽额鲈属均未能形成独立分支,而是与石斑鱼属种类聚在一起,显示其与石斑鱼属有很近的亲缘关系,部分可能是石斑鱼属的特化类群。

In this study,40 groupers belonging to 10 genera of the subfamily Epinephelinae from Western Pacific were collected,and partial sequences of 16S rRNA gene and COI gene were amplified and determined.The molecular phylogenetic relationships were constructed and analyzed using maximum likelihood method.The results showed that the length of COI gene was 651 bp,encoding 227 amino acids.While the consensus sequences of 16S rRNA gene were 566 bp,with certain base insertion and deletion.The sequences of 16S rRNA gene were more conserved than those of COI gene.The phylogenetic tree of the 10 genera of the subfamily Epinephelinae was constructed and the results showed that Plectropomus was first separated and rooted at the base of the tree,indicating its evolutionary status was most primitive.6 species from Plectropomus were clustered as a monophyletic group.Aethaloperca was close to Cephalopholis,which tightly clustered together.Variola was located between Plectropomus and Cephalopholis.Epinephelus was located at the top of the tree,indicating its advanced evolutionary status.The species from Epinephelus in the tree were clustered as two parallel branches,instead of a monophyletic group;Cromileptes,Triso,Hyporthodus,Anyperodon and Promicrops could not form an independent branch but cluster together with species from Epinephelus,indicating their close relationship within Epinephelus and some species might belong to Epinephelus.