鳗鲡属6种鱼类线粒体COⅠ和COⅡ基因序列分析和分类的有效性  

The sequencing analysis and taxonomic effectiveness of Anguilla six eels based on mtDNA CO Ⅰ and CO Ⅱ gene sequence

作　　者：龚小玲[1] 岳丽佳[1] 崔忠凯[1] 张晓懿[1] 

机构地区：[1]上海海洋大学省部共建水产种质资源发掘与利用教育部重点实验室,上海201306

出　　处：《上海海洋大学学报》2013年第4期524-530,共7页Journal of Shanghai Ocean University

基　　金：国家自然科学基金(31201995);上海市科技攻关项目(10dz1200804);上海市重点学科项目(S30701)

摘　　要：对鳗鲡属(Anguilla)的美洲鳗鲡(A.rostrata)、欧洲鳗鲡(A.anguilla)、太平洋双色鳗鲡(A.bicolor pacifica)、花鳗鲡(A.marmorata)、澳洲鳗鲡(A.australis)、日本鳗鲡(A.japonica)6种鱼类54个体COⅠ和COⅡ基因片段中1 179 bp和633 bp的序列特征、分子分类的有效性、以及构建的系统关系进行了比较分析,结果表明:(1)COⅠ和COⅡ基因可变位点、简约信息的百分比分别为17.98%、16.45%和12.16%、10.11%,COⅠ较COⅡ基因的变异率高;(2)两种基因序列均表现出明显的反G偏倚(在COⅠ和COⅡ中G的百分含量分别为18.45%,16.67%);(3)基于COⅠ基因种间遗传距离均高于COⅡ基因,且均大于2%(欧洲鳗鲡和美洲鳗鲡基于COⅡ基因序列的种间遗传距离为1.8%除外),种内遗传距离都小于1%;(4)以两序列构建的系统树,各物种所有个体均形成独立、高支持率单系,但两序列构建的系统关系并不完全一致。由此说明,COⅠ和COⅡ都能对鳗鲡属鱼类进行有效的物种分子鉴定,但在探讨鳗鲡属鱼类系统进化关系上还需要联合其它基因。Six species of genus Anguilla, including Anguilla rostrata, A. anguilla, A. bicolor pacifica, A. marmorata, A. australis and A. japonica are cultured in China. Misidentification on the fry will impact farmers＇ income because of different AnguiUa species with different prices in China. In this study, we tried to use two molecular markers （ 1179bp-length mitochondrial CO I gene and 633bp-length COⅡ gene） to discriminate the six species based on 54 fry individuals. The percentage of variable sites in COⅠ and COⅡ was 17.98% and 16.45% respectively. And the percentage of parsimony-informative sites was 12.16% and 10.11% in COⅠ and COⅡ.The negative bias for G was observed in both COⅠ and CO Ⅱ genes in checked samples, and their G frequences were 18.45% and 16.67% respectively. The pairwise distances based on either COⅠ or CO Ⅱ among six eel species were almost more than 2% except for only one between A. rostrata and A. anguilla based on CO Ⅱ , and the former was a little higher than the latter. But the genetic distances within each species were all less than 1% based on two genes. Although there existed a small difference between two cluster results of six eel species ,which was based on CO Ⅰ gene or CO Ⅱ gene, all individuals of each species formed a strong monophyletic group on NJ and Mrbayes trees. Taken together, both CO Ⅰand COⅡ genes are good molecular markers to be used in species identification in genus Anguilla, and our results may be helpful for eel aquaculture industry in China.

关 键 词：鳗鲡属 COⅠ基因序列 COⅡ基因序列 物种鉴定 系统关系 

分 类 号：S917[农业科学—水产科学]