中国南海康氏马鲛线粒体COI序列遗传变异分析  

Genetic variation of mt DNA COI sequence of Scomberomorus commerson populations in the South China Sea

作　　者：曹艳[1] 章群[1] 宫亚运 吕金磊[1] 杨喜书 

机构地区：[1]暨南大学生态系,广东广州510632

出　　处：《南方水产科学》2016年第5期53-60,共8页South China Fisheries Science

基　　金：国家自然科学基金项目(41071034);中央高校基本科研业务费专项资金项目(21613105);欧盟Erasmus Mundus TECHNO I博士后交流项目

摘　　要：在测定的采自广东饶平、阳江和广西东兴海域的62尾康氏马鲛（Scomberomorus commerson）线粒体COI基因711 bp序列中,共检测到26个变异位点,18个单倍型,总体呈现出高单倍型多样性（Hd=0.808±0.040）和低核苷酸多样性（π=0.004 0±0.000 6）的特点。邻接树上出现了3个分支,分支间Fst为0.811-0.833且P〈0.001,Nm为0.1-0.117;AMOVA分析显示分支间遗传变异占82.61%。表明3个分支间分化程度高,推测分歧时间为（89-22.67）万年前中更新世时期,可能原因是受到更新世冰期和间冰期交替的影响。但分支内与分支间都有不同地理来源的个体,没有出现明显的地理聚群;不同地理群体间Fst为-0.027-0.066,Nm均大于4或小于0;群体内个体间变异为96.34%。均表明群体间基因交流频繁,遗传分化程度并不高。3个分支中Clade A分支经历过种群快速扩张事件,可能是末次冰期期间康氏马鲛进入外海并受洋流及生存空间改变的影响。We analyzed 711 bp segment of the mt DNA cytochrome oxidase subunit I of 62 individuals of Scomberomorus commerson collected from Raoping,Yangjiang in Guangdong Province and Dongxing in Guangxi Province,among which 26 mutations and 18 haplotypes were detected. Generally,the haplotype diversity（ Hd= 0. 808 ± 0. 040） level was relatively high,while the nucleotide diversity was much poorer（ π = 0. 004 0 ± 0. 000 6）. Three shallow clades appeared in the Kimura 2-parameter based on neighbor-joining tree and parsimony network; pairwise fixation index Fstvalue ranged from 0. 811 to 0. 833（ P 0. 001）; gene flow ranged from 0. 1 to0. 117. Analysis of molecular variance shows that the genetic variation among three clades was 82. 61%,suggesting significantly high genetic differentiation. The deduced divergence time was about 890 - 226. 7 ka BP（ i. e.,during the middle Pleistocene period）,and the Glacial interglacial cycles in Pleistocene might be the reason of genetic differentiation. However,individuals from various locations were intertwined together in all clades; pairwise Fst（- 0. 027 - 0. 066） and gene flow among sampling sites revealed no significant differentiation. AMOVA analysis shows that the percentage of population variation was 96. 34%,suggesting a relatively high level of gene flow among sampling sites in the South China Sea. In Clade A,the significant negative values of neutral test and the unimodal mismatch distribution suggest a recent population expansion occurred in this clade about 890 000 - 226 700 years ago,due to the effects of changed living space and marine currents during Pleistocene glaciations.

关 键 词：康氏马鲛 线粒体COI序列 遗传变异 种群结构 中国南海 

分 类 号：Q347[生物学—遗传学]