渤海湾7种虾虎鱼科鱼类COI基因序列特征及分子分类研究

Sequence and Molecular Classification of COI Gene of Seven Species of Goby from the Bohai Bay

为获得渤海湾天津海域常见虾虎鱼线粒体条形码序列及系统分类信息,采集渤海湾7种虾虎鱼样本,通过形态初步鉴定物种,并提取DNA进行线粒体COI基因部分序列扩增测序,用系统进化分析及分子鉴定软件MEGA对渤海湾常见12种虾虎鱼COI基因部分片断进行序列特征分析及分子分类分析。扩增得到7种虾虎鱼COI基因片断,分析得到其平均GC含量低于AT含量,碱基在密码子位置分布中具有偏向性,且GC含量最高为第2位碱基,与多种鱼类COI基因碱基特点相似。基因密码子碱基变异率为19.4%,转换颠换比为1.3。遗传距离分析及系统进化树分析理清了渤海湾天津海域12种主要虾虎鱼的系统分类及进化关系。遗传距离显示,矛尾刺虾虎鱼(Amblychaeturichthys hexanema)和斑尾复虾虎鱼(Synechogobius ommaturus)为同种鱼。虾虎鱼COI编码基因密码子高变异率可能与其良好的环境适应性有关。

In order to clarify the mitochondrial barcode sequence and taxonomic information of common goby fish in Tianjin area of Bohai Bay,seven species of goby fish were collected from Bohai Bay,identified by morphology,and DNA was extracted for amplification and sequencing of mitochondrial COI gene fragments.Phylogenetic analysis and molecular identification software MEGA were used to analyze the sequence characteristics and molecular classification of COI gene fragments of 12 common goby species in Bohai Bay.Seven COI gene fragments of Goby were amplified and sequenced,the average GC content was lower than AT content,the base had a bias in the codon position distribution,and the highest GC content was the second base,which was similar to the COI gene base of many fishes.The codon base variation rate was 19.4%,and the ratio of transitions to transversions was 1.3.Phylogenetic distance analysis and phylogenetic tree analysis clarified the phylotaxonomic and evolutionary relationships of 12 major goby species in Tianjin area of Bohai Bay.Genetic distance indicated that Amblychaeturichthys hexanema and Synechogobius ommaturus were the same species.The high codon variation rate of codon encoding gene in Goby may be related to its good environmental adaptability.