印度-太平洋石鲈亚科鱼类DNA条形码及分子系统进化研究

DNA BARCODING FOR WORLDWIDE HAEMULINAE IN CLASSIFICATION AND PHYLOGENY

为探讨DNA条形码基因COⅠ序列在石鲈亚科鱼类物种鉴定的有效性,本研究分析了印度-太平洋区域的石鲈亚科7个属29种鱼类9个个体长度为651 bp的COⅠ基因序列,利用MEGA 5.0计算石鲈亚科种内与种间的遗传距离,并基于最大简约法与最大似然法构建了其分子系统进化关系。结果显示:石鲈亚科鱼类种间遗传距离在0.021—0.240之间,平均遗传距离0.184;种内遗传距离在0.000—0.009之间,平均0.004。其中种间平均遗传距离(0.184)显著大于种内平均遗传距离(0.004),种间遗传距离是种内的46倍。同时,各物种间遗传距离均大于Hebert推荐区分物种的最小种间遗传距离0.02(2%)。基于COⅠ序列构建的系统进化树,同一物种不同个体间均能聚成独立的单系,表明COⅠ基因可作为石鲈亚科物种准确鉴定的有效条形码基因。同时,系统进化树上,石鲈属是非单系类群,主要形成5个分支,而不同分支的种类与其地理分布存在一定的相关性,与近年部分分子系统地理学的研究观点一致。

To investigate the feasibility of using CO I sequences as DNA barcodes to identify Haemulinae species, we determined the 651 bp CO I sequences of 91 Haemulinae individuals sampled from 7 genera 29 species, calculated the genetic distances inter- and intra-species using MEGA 5.0, and constructed the molecular phylogenetic trees using maximum parsimony and maximum likelihood methods. The result show that the inter-species genetic distance was 0.021--0.240 in average of 0.184, while that of intra-species was 0.000--0.009 in average of 0.004. The average inter-species value （0.184） is 46 times larger than that of intra-species one （0.004）. Moreover, each inter-species genetic distance value is larger than the minimum species identification value 0.200 （2%） suggested by Hebert. In the molecular phylogenetic trees, individuals of each species formed an independent monophyletic group, indicating that CO I could be used as an effective barcode gene for accurate identification among Haemulinae species. Meanwhile, as the phylogenetic trees show, the Pomadasys fish are non-monophyletic and form 5 independent groups. Such phylogenetic relationships are due to their geographic distribution, which is consistent with the viewpoint of modem molecular phylogeography studies.