基于线粒体COⅠ基因的DNA条形码在沼虾属种类鉴定中的应用  

Application of COⅠ-based DNA barcoding in Macrobrachium identification

作　　者：郭照良 郑小壮 陈文坚 郭国才 陈清华 GUO Zhaoliang;ZHENG Xiaozhuang;CHEN Wenjian;GUO Guocai;CHEN Qianghua(School of Life Science and Engineering,Foshan University,Foshan,Guangdong 528231,China;South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou,Guangdong 510520,China;Huizhou Fisheries Research Promotion Center,Huizhou,Guangdong 516002,China)

机构地区：[1]佛山科学技术学院生命科学与工程学院,广东佛山528231 [2]生态环境部华南环境科学研究所,广东广州510520 [3]惠州市渔业研究推广中心,广东惠州516002

出　　处：《湖南农业大学学报（自然科学版）》2019年第5期514-521,共8页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：国家环保专项(PM–zx097–201812–244);2019年广东大学生科技创新培养专项(pdjh2019b0510);广东省动物分子设计与精准育种重点实验室项目(2019B030301010);佛山科学技术学院项目(kh19051)

摘　　要：为探索DNA条形码在沼虾属(Macrobrachium)种类鉴定中的可行性,对21种沼虾(亚洲群体7种和美洲群体14种)的COⅠ基因片段序列进行分析。结果显示:沼虾COⅠ基因组成偏倚明显,AT含量(57.74%)高于GC(42.26%),GC在各个密码子位点的含量由高到低分别为第1密码子位点(49.24%)、第2密码子位点(40.72%)、第3密码子位点(36.82%);基于Kimura 2–Parameter模型分析21种沼虾的种间和种内平均遗传距离分别为0.753和0.005,种间平均遗传距离是种内遗传距离的150.6倍,符合HEBERT所推荐的鉴定不同物种的最小有效种间遗传距离为0.02以及种间遗传距离大于或等于10倍种内遗传距离的标准;在分子系统发育树中,NJ树和ML树的拓扑结构基本一致,亚洲种群和美洲种群分别以100%和82%的置信度形成2个姐妹支,并且同种沼虾都以较高的置信度聚集在同一分支内。研究结果证明,线粒体COⅠ基因能有效地对沼虾属的种类进行鉴别。In order to verify the feasibility of DNA barcoding in the identification of Macrobrachium species,this study analyzed the sequence of COⅠgene fragments of 21 species of Macrobrachium.The results showed that the COⅠgene composition of the Macrobrachium was significantly biased,with higher AT content(57.74%)and lower GC content(42.26%).The content of GC at each codon site from high to low is the first codon(49.24%),the second codon(40.72%),and the third codon(36.82%).Based on the Kimura 2-Parameter model,the interspecific and intraspecific genetic distances of 21 species of Macrobrachium were 0.753 and 0.005,respectively.The average genetic distance between species was 150.6 times of the intraspecific genetic distance,which was consistent with the minimum effective interspecies genetic distance for identifying different species is 0.02 and the genetic distance between species is greater than or equal to 10 times the genetic distance within the species recommended by Hebert.In the molecular phylogenetic tree,the topological structure of the NJ tree and the ML tree are basically the same,and the Asian and American populations form two sister branches with 100%and 82%confidence,respectively,and the same species of Macrobrachium are clustered in the same branch with high confidence.The results show that the mitochondrial COⅠgene can accurately identify the species of Macrobrachium.

关 键 词：沼虾属 DNA条形码 COⅠ基因 鉴定 

分 类 号：S917.4[农业科学—水产科学]