秘鲁外海茎柔鱼大型群与小型群的遗传变异分析  

Genetic variation analysis on large-sized group and small-sized group of Dosidicus gigas off Peru Exclusive Economic Zones

作　　者：刘连为[1,2] 陈新军[1,3,4,2] 许强华[1,3,4,2] 陆化杰[1,3,4,2] 王从军[1,2] 

机构地区：[1]上海海洋大学海洋科学学院,上海201306 [2]远洋渔业协同创新中心,上海201306 [3]大洋渔业资源可持续开发省部共建教育部重点实验室,上海201306 [4]国家远洋渔业工程技术研究中心,上海201306

出　　处：《海洋渔业》2014年第3期216-223,共8页Marine Fisheries

基　　金：国家自然科学基金(NSFC41276156);国家863计划(2012AA092303);国家发改委产业化专项(2159999);上海市科技创新行动计划(12231203900)

摘　　要：秘鲁海域茎柔鱼（Dosidicus gigas）资源丰富,且存在不同性成熟胴长群体.为了更好地对该海域茎柔鱼资源进行开发管理,本文利用线粒体DNA（mtDNA）与微卫星DNA（SSR）2个分子标记对秘鲁外海茎柔鱼大型群与小型群的遗传变异进行研究.基于Cytb基因序列得到的2个群体总的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为19、0.758±0.052、0.002 19±0.001 46和1.586.基于COI基因序列得到的2个群体总的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为18、0.707±0.055、0.001 70±0.001 26和1.057.2个群体具有较高的单倍型多样性指数和较低的核苷酸多样性指数.筛选的12个SSR位点均为高度多态性位点（PIC=0.725～0.933）,位点DG02、DG07、DG09、DG28、DG36极显著偏离Hardy-Weinberg平衡（P＜0.01）.基于SSR标记得到的大型群观测杂合度为0.716,期望杂合度为0.868;小型群观测杂合度为0.721,期望杂合度为0.883,二者均具有较高的遗传多样性.基于mtDNA标记的单倍型网络关系图及2个群体间遗传分化系数Fst分析结果显示,2个群体不存在显著的遗传分化（Cytb：Fst=0.004 52,P＞0.05;CO Ⅰ：Fst=0.000 89,P＞0.05）.基于SSR标记也得出相同的结论（Fst=0.002 51,P＞0.05）.2个群体可能在产卵洄游过程中发生基因交流,建议将秘鲁外海茎柔鱼大型群和小型群看作1个管理单元.Dosidicus gigas is widely distributed in the eastern Pacific, and the highest concentrations are found from the Gulf of California to northern Chile, especially off the coast of Peru. Several size-at-maturity groups of D. gigas have been distinguished on the basis of mantle length of adult males and females. In order to exploit and manage this squid scientifically, genetic variation between large-sized group and small-sized group of D. gigas off Peru Exclusive Economic Zones （EEZ） was investigated based on mitochondria DNA markers and microsatellite DNA markers. Results showed that the number of haplotype, haplotype diversities, nucleotide diversities and average nucleotide differences of all individuals were 19, 0. 758±0. 052, 0. 002 19 ±0.001 46 and 1. 586 by Cytb sequences, and 18, 0. 707 ±0. 055, 0. 001 70±0.001 26 and 1. 057 by CO Ⅰ sequences, respectively. Two size-at-maturity groups of D. gigas were characterized by higher haplotype diversity and lower nucleotide diversity. All 12 loci were highly polymorphic （ PIC = 0. 725 - 0.933 ） , and loci DG02, DG07, DG09, DG28 and DG36 deviated extremely and significantly from Hardy- Weinberg equilibrium after Bonferroni corrections （P 〈 0.01 ）. The observed heterozygosity and expected heterozygosity of large-sized group were 0.716 and 0. 863 respectively, and those of small-sized group were 0.721 and 0. 883 respectively, which all showed high genetic diversities. Median network and pairwise fixation index Fst revealed that no significant genetic differentiations existed between two size-at-maturity groups （Cytb ： Fst = 0. 004 52, P 〉 0.05 ; CO Ⅰ ： Fst = 0. 000 89, P 〉 0.05） based on mitochondria DNA markers. The same conclusion was also drawn out based on microsatellite DNA markers （ Fst = 0. 002 51, P 〉 0.05 ）. This might be caused by gene flow between two size-at-maturity groups as they carried out spawning migration. It is suggested that two size-at-maturity groups of D. gigas off Peru EEZ should be considered to be one ma

关 键 词：茎柔鱼 大型群 小型群 遗传变异 线粒体DNA标记 微卫星标记 

分 类 号：Q75[生物学—分子生物学]