基于RAG2基因序列分析仿石鲈科鱼类及其相关种类系统进化关系

摘要

为探讨仿石鲈科鱼类目前存在的分类争议问题,测定了仿石鲈科(Haemulidae),金线鱼科(Nemipteridae),眶棘鲈属(Scolopsis)等相关科属共33种鱼类RAG2基因部分序列,利用最大简约法(MP法)和贝叶斯分析法(BI法),并以黄鹦嘴鱼作为外类群构建分子系统进化树.结果显示,33种鱼类共形成三大类群,其中仿石鲈科8个属聚成一类群,金线鱼属和眶棘鲈属的种类聚成另一类群,眶棘鲈属未能与仿石鲈科形成单系.同时,基于属间遗传距离比较,眶棘鲈属与金线鱼科的遗传距离比其与仿石鲈科各属的遗传距离要小得多,表明眶棘鲈属与金线鱼科有更近的亲缘关系,支持眶棘鲈属隶属于金线鱼科的观点.此外,传统分类资料中归类于仿石鲈科的髭鲷属(Hapalogenys)也没有与仿石鲈科聚成单系,而是独自形成一支,位于进化树基部,显示出髭鲷属与仿石鲈科关系较远,与近年来认为髭鲷属应该从仿石鲈科中划分出去的结果一致.在仿石鲈科内部,少棘胡椒鲷属(Diagramma)中的少棘胡椒鲷与胡椒鲷属(Plectorhinchus)的种类关系很近.在进化树上,少棘胡椒鲷位于胡椒鲷属的内部,花尾胡椒鲷最先分化出来,位于该分支基部,支持少棘胡椒鲷归为胡椒鲷属,名称沿用原来的学名胡椒鲷的观点.%To reveal the current classification problems (that) existed in Haemulidae species,partial sequences of nuclear DNA marker RAG2 of 33 species from Haemulidae,Nemipteridae and Scolopsis were determined in this study.Molecular phylogenetic trees were constructed using maximum parsimony (MP) and Bayesian inference (BI) methods and Scarus frenatus as outgroup.The result showed that three big clades were formed in the trees.8 genera of Haemulidae were grouped in one clade,Nemipteridae and Scolopsis were grouped in another clade.Species of Scolopsis and Haemulidae could not form a monophyletic group in the trees.Based on the genetic distance data,the distance values between Scolopsis and Nemipteridae were much smaller than the values between Scolopsis and Haemulidae,indicating that Scolopsis had a closer relationship with Nemipteridae than Haemulidae.This result supported the view that Scolopsis might be included in the family Nemipteridae.In addition,the traditionally Haemulidae-classified genus Hapalogenys was not grouped within Haemulidae either.Three Hapalogenys species formed an independent branch and were located at the base of the phylogenetic tree,suggesting a distant relationship between Hapalogenys and Haemulidae.This result was consistent with the current view that Hapalogenys should be removed from Haemulidae.Within the inner species relationships of Haemulidae,Diagramma pictum was revealed to be located in the internal position of the Plectorhinchus group and sister to Plectorhinchus orientalis,and the specie Plectorhinchus cinctus was found to be first separated and positioned at the base of this group.The result suggested a very close relationship between D.pictum and Plectorhinchus and supported the view that D.pictum was classified to Plectorhinchus with the name changed into its original name Plectorhinchus pictus.