利用线粒体DNA标记分析中国东南沿海拟穴青蟹种群遗传结构  

Population genetic structure of Scylla paramamosain from the coast of the Southeastern China based on mtDNA COI sequences

作　　者：路心平[1,2,3] 马凌波[2] 乔振国[2] 张凤英[2] 马春艳[2] 

机构地区：[1]中国科学院海洋研究所,山东青岛266071 [2]中国水产科学研究院东海水产研究所农业部海洋与河口渔业重点开放实验室,上海200090 [3]中国科学院研究生院,北京100049

出　　处：《水产学报》2009年第1期15-23,共9页Journal of Fisheries of China

基　　金：国家科技支撑计划专题(2006BAD03B08-09);中央级公益性科研院所基本科研业务费重点项目(2007Z01);国家科技基础条件平台建设子项目课题(2004DKA30470-004)

摘　　要：为研究我国东南沿海拟穴青蟹(Scylla paramamosain)的种群遗传结构,对10个地理种群130只拟穴青蟹的线粒体DNA(mitochondrial DNA,mtDNA)细胞色素氧化酶亚基I(COI)基因片段序列进行分析。522 bp的DNA片段共发现17个变异位点,定义了21种单倍型,其中单倍型2为10个地方种群的共享单倍型,占个体总数的56.15%,而大部分单倍型为稀有单倍型,只在少数种群的个别个体中出现。10个种群的单倍型多样性水平为h=0.6738,核苷酸多样性水平为π=0.1987%,基本呈由南到北递减的趋势。10个种群的总体遗传分化程度较低(FST≈0.05),但是极为显著(P<0.005)。基于单倍型频率和序列遗传距离法分析的共同结果,广西北海种群与大多数种群的遗传分化显著,而海南三亚种群分别与海南红树林和广东台山种群遗传分化显著。Mantel检验显示种群间的遗传分化程度与地理距离没有显著的相关性。分子进化中性检验结果表明,自然选择在分子进化过程中起了重要作用,并暗示该物种在最近经历了一个快速的种群爆发及扩张事件。Scylla paramamosain （ Decapoda： Portunidae） is a swimming crab that is widespread in the coast of Southeastern China and commonly found in estuarine and mangrove waters. Although it has been reported that no significant morphological and isozyme differences were found among populations of S. paramamosain in China, it is still necessary to study the genetic structure of S. paramamosain by more sensitive and stable molecular markers. Genetic diversity and structure of 10 populations of S. paramamosain were investigated and analyzed at the mtDNA label in this study. A total of 130 crabs from ten representative localities along the coast of Southeastern China were collected. A 522bp length fragment of the mitochondrial DNA cytochrome oxidase subunit Ⅰ （mtDNA CO1） gene was amplified and sequenced. Intraspecific variation of mtDNA COI gene was investigated in 130 individuals. We examined 522 base pairs （bp） and identified 21 different haplotypes. Each population sample is characterised by a single most frequent haplotype （Hap 2 ） with the highest frequency of 56.15%, shared among all ten populations, and a small number of rare ones, typically present in only one or two individuals and representative of several specific populations. The average haplotype （h） and nucleotid diversity （π） of ten populations is 0.6738 and 0. 1987%, respectively. Analysis of molecular variance （AMOVA） and FST statistics analysis of mtDNA haplotype frequencies and sequence divergence data revealed a significant genetic differentiation （ FST = 0. 05, P 〈 0. 005 ） among populations. In pairwise population comparisons, a highly significant genetic differentiation exists only between population BH and other 5 populations based on Fsr values from haplotype frequency and distance method, while population SY differs from HSL and TS significantly. Using a Mantel test, we found no significant correlation between pairwise population FST values （estimated by haplotypic frequencies） and geographic distances, sug

关 键 词：拟穴青蟹 细胞色素氧化酶亚基Ⅰ 单倍型 种群遗传结构 

分 类 号：Q347[生物学—遗传学] S917[农业科学—水产科学]