中国蓑鲉亚科鱼类DNA条形码及分子系统进化研究

DNA barcoding and molecular phylogeny of Pteroninae species in China sea

为从分子水平分析我国蓑鲉亚科鱼类分类关系,通过PCR扩增及测序获得了我国8种蓑鲉亚科鱼类COⅠ基因部分序列,结合GenBank下载的6种蓑鲉,共计14种40个个体线粒体COⅠ基因序列,利用MEGA X计算了序列信息和遗传距离,利用基于最大似然法和邻接法构建分子系统进化树。结果显示:除盔蓑鲉(Ebosia bleekeri)和安狭蓑鲉(Pteroidichthys amboinensis)只有一个样本无法测定外,其余12种蓑鲉亚科鱼类的种间平均遗传距离是种内平均遗传距离的69.17倍,显示COⅠ基因可作为蓑鲉亚科鱼类的有效DNA条形码基因。进化树上,蓑鲉亚科部分属并未能聚成属间单系,其中蓑鲉属(Pterois)与短鳍蓑鲉属(Dendrochirus)在进化树上形成多个分支。在蓑鲉属中,翱翔蓑鲉(P.volitans)与斑鳍蓑鲉(P.miles)聚为一支,两者关系较近,但COⅠ遗传距离为0.042,大于Hebert推荐的0.020作为最小区分物种的遗传距离,支持两者为两个独立物种的观点;触须蓑鲉(P.antennata)、辐蓑鲉(P.radiate)和黑颊蓑鲉(P.mombasae)聚为一支,独立于翱翔蓑鲉与斑鳍蓑鲉的分支之外,并与短鳍蓑鲉属(Dendrochirus)的花斑短鳍蓑鲉(D.zebra)以及盔蓑鲉属(Ebosia)的种类聚在一起,与近期有关蓑鲉亚科各种属分子聚类研究结果相似;但这3种蓑鲉是否可以从蓑鲉属中独立出来归为Pteropterus属,还需要后续更多的蓑鲉亚科鱼类样品研究验证。

Pteroninae fishes,commonly known as lionfish,are diverse species mainly found in the oceanic waters of tropical,subtropical areas throughout the Indo-Western Pacific.Recently,Pteroninae fishes are still confronted with taxonomic problems because of their identical morphological characteristics.To investigate the availability of mitochondrial cytochrome oxidase subunit I(COⅠ)sequences as DNA barcodes for Pteroinae species identification,partial COⅠsequences of 8 Pteroinae speices from China were obtained by PCR amplification and sequencing.Combining with sequences obtained from GenBank,COⅠsequences of 40 individuals in 14 Pteroinae species were analyzed.The sequence information and genetic distances were calculated using MEGA X,molecular phylogenetic trees were constructed and analyzed basing on the maximum likelihood and neighbour-joining method.The result showed that:In the length of 639 bp consensus sequence,the base composition was A:23.7%,T:29.6%,C:26.8%and G:19.8%.421 sites were conservative(65.9%),218 sites were variable(34.1%)and 191 sites were parsim-informative(29.9%).In genetic distance,except for one each undeterminable sample of Ebosia bleekeri and Pteroidichthys amboinensis,the average intra-species genetic distance values of the rest 12 Pteroinae species was 0.0024;while the average inter-species genetic distance was 0.166,which was 69.17 times of the former,revealing that COⅠgene could be used as an effective DNA barcode gene for identifying Pteroinae species.In Pteroinae molecular phylogenetic trees,except for genus Pteroidichthys,which was first separated and located at the base of the tree,other genera in Pteroinae could not form a monophyletic group,especially the species-rich genera Pterois and Dendrochirus,forming more branches in the tree.In the genus Pterois,two independent branches formed,two species:P.volitans and P.miles,tightly clustered together as one branch,indicating their close relationship,but the COⅠgenetic distance values were 0.042,greater than the minimum distance value(0.020)for species identification recommended by Hebert,supporting the recent opinions that they might be independent species.The other three Pterois species P.antennata,P.radiate and P.mombasae clustered as another branch,independent to the cluster(P.volitans+P.miles)and closely related to Dendrochirus zebra and Ebosia species.Such relationships were also found in the recent molecular phylogenetic studies,indicating that they might be two independent groups in Pterois.However,whether the three Pterois species would be seperated from Pterois and classified into genus Pteropterus,more Pteroinae species samples should be collected and analyzed in further studies.