基于线粒体Cytb基因探讨我国日本囊对虾4个地理群体的遗传结构及种群分化  

Genetic Structure and Population Differentiation in Four Wild Populations of Marsupenaeus japonicus Based on Cytochrome b Gene Segment Sequence of Mitochondrial DNA

作　　者：曾凡荣[1] 王军[1] 周孔霖[1] 游欣欣[1] 毛勇[1] 

机构地区：[1]厦门大学海洋与环境学院,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2010年第5期701-706,共6页Journal of Xiamen University：Natural Science

基　　金：农业部公益性行业科研专项(200803012)

摘　　要：利用线粒体细胞色素b基因序列分析了4个不同地理群体（北海群体、陵水群体、惠来群体和厦门群体）的野生日本囊对虾（Marsupenaeus japonicus）的群体遗传结构.以特异引物进行PCR扩增,获得了日本囊对虾530 bp的基因片段序列.序列分析结果表明,在120个日本囊对虾个体中,共检测到75个多态位点,获得62个单倍型,其中有44个简约信息位点,占整段序列的8.3%.各单倍型变异无碱基的插入或缺失,全部为转换或颠换,碱基频率含量（fA＋fT）为59.4%,大于（fG＋fC）（40.6%）.核苷酸多态性以惠来群体最高,其它3个群体较低.群体内遗传距离为0.4 5%~2.6 0%,群体间遗传距离在0.50%~5.30%之间.采用分子方差分析（AMOVA）方法,结果显示,群体间遗传变异占总变异的69.9%,群体内的遗传变异占总变异的31.1%,群体间变异是总变异的主要来源.构建的4个群体分子系统树表明,北海群体、陵水群体和部分惠来群体由于亲缘关系较近而聚在一起,而厦门群体则和部分惠来群体聚成另一支,两支的平均遗传距离为5.17%,分化接近亚种水平,据此认为我国东南近海的日本囊对虾可以分为2个种群,2个种群的分布区域在广东惠来海域附近存在重叠.Genetic structure and population differentiation in four wild populations of Marsupenaeus japonicus,collected from Lingshui in Hainan province,Beihai in Guangxi,Huilai in Guangdong and Xiamen in Fujian,were studied in the present paper based on sequencing 530 bp cytochrome b（Cytb） gene segment.75 variable sites were identified from 120 individuals,with 62 haplotypes,and 44 were parsimony sites,accounting for 8.3% of total sequence.They were all transitional or transversional variations and no indels were found.The content of（fA＋fT）（59.4%） was much more than that of（fG＋fC）（40.6%）.The index of nucleotide diversity in the Huilai population was the largest among the four populations.Genetic distance within the populations was from 0.45% to 2.60%,and 0.50% to 5.30% between the populations.AMOVA analysis disclosed that variation between populations accounting for 69.9% of total variation,suggesting that variations occurred between populations were the main source of the total variation.The NJ tree of the four putative populations showed the Beihai,Lingshui and part of Huilai putative populations had the closest relation among the four groups and they clustered to form one branch,while Xiamen and the rest Huilai putative populations clustered to the other,and the genetic distance of these two groups was 5.17%.Result in this study suggests that the genetic divergence between the two groups may be approached to subspecies level,and it was concluded that the M.japonicus found in southeast coast of China were separated two distinct clades representing two varieties,and the Huilai coast constitute the sympatric zone of the two varieties.

关 键 词：日本囊对虾 细胞色素B基因 遗传多样性 

分 类 号：P745[天文地球—海洋生物学]