中国沿海龙虾属8种龙虾COI基因序列的分子系统学研究

The Molecular Phylogeny on Eight Species of Panulirus Genus from the Chinese Coast Based on COI Gene Sequence

我国沿海分布8种龙虾属的龙虾,为了研究其系统发育和筛选分类DNA条形码,对线粒体COI基因序列进行分析,用MEGA4.0软件计算遗传距离,采用邻接法(NJ)和最大简约法(MP)构建分子系统发育树。结果获得大小为731 bp,GC含量在40.2%～44.5%之间COI基因片段。8种龙虾种内变异较小,遗传距离范围0.00～0.057,平均0.016;种间遗传距离较大,介于0.124～0.228之间,平均遗传距离为0.185,种内和种间遗传距离相差约10倍。NJ树和MP树都支持8种龙虾分成2支:密毛龙虾、长足龙虾和日本龙虾为一支,中国龙虾、杂色龙虾、黄斑龙虾、锦绣龙虾和波纹龙虾等5种龙虾为另一支。表明COI基因序列作为DNA条形码进行龙虾属的分类鉴定具有一定的可行性。

To study the phylogeny and select a DNA barcode for classification,the mitochondrial COI genes of eight lobster species,belong to the genus Panulirus,distributing along the coast of China were sequenced and analyzed.The genetic distance was calculated using MEGA4.0,and the phylogenetic trees were constructed with Neighbor-Joining（NJ） and Maximum Parsimony（MP） methods.The obtained COI gene fragments were 731 bp with GC contents ranging from 40.2% to 44.5%.The intraspecific genetic distances of these eight species,ranging from 0.00~0.057 with an average of 0.016,are small,and the interspecific genetic distances,ranging from 0.124 to 0.228 with an average of 0.185,are more than ten times higher than those of intraspecies.Eight species of Panulirus can be divided into two branches by NJ tree and MP tree： P.japonicus,P.longpies and P.penicillatus belong to a same branch;P.stimpsonic,P.polyphagus,P.versicolor,P.ornatus and P.homarus belong to the other.The results indicated that the COI gene could be a useful DNA barcode for taxonomic identification of lobsters.