西施舌5个地理群体ITS1序列变异及系统发生分析  

ITS1 sequences variation and phylogenetic analysis on five geographical stocks of Coelomactra antiquata

作　　者：孟学平[1] 高如承[2] 申欣[1] 王帅[2] 程汉良[1] 董志国[1] 阎斌伦[1] 

机构地区：[1]淮海工学院海洋学院江苏省海洋生物技术重点实验室,连云港222005 [2]福建师范大学生命科学学院,福州350108

出　　处：《生态学报》2010年第20期5555-5561,共7页Acta Ecologica Sinica

基　　金：江苏省自然科学基金项目(BK2007066);国家863计划(2004AA603140);江苏省教育厅自然科学基金项目(05SJD240028)

摘　　要：利用核糖体rRNA基因第一内转录间隔区(ITS1)序列,对我国山东日照(RZ)、江苏连云港(LYG)和启东(QD)、福建长乐(CL)、广西北海(BH)沿海西施舌5个野生群体的遗传结构进行了分析。经PCR扩增、克隆、非克隆测序,获得长度为816—843bp的ITS1核苷酸序列,其平均G+C含量(60.8%)显著高于A+T含量。在西施舌5个群体93个个体118个序列中共检测到153个变异位点,多态位点比例为18.3%,其中,简约信息位点为63个,共有63种基因型。群体间遗传距离在0.74%—3.38%之间,群体内遗传距离为0.72%—1.06%之间。CL群体与其他4个群体间的遗传距离明显高(3.17%—3.38%)。AMOVA分析结果显示长乐群体有明显的遗传分化(FST=0.670—0.702,P(0.001)。以中国蛤蜊为外群构建的NJ树和ML树显示CL群体聚为一支,非长乐群体互相重叠聚为另一支,研究结果显示,长乐群体已经形成了具有明显遗传结构的地理种群。Coelomactra antiquata Spengler,1802,called Xishishe in Chinese,is a bivalve,which belongs to the phylum Mollusca,the class Bivalvia,the order Veneroida,the family Mactridae and the genus Coelomactra.The species is distributed widely in the western Pacific Ocean,along the coast of Indochina,Japan,Korea and China.C.antiquata has a wide but erratic distribution in China from Taiwan,Guangdong and Hainan Provinces in the south northward to the Shandong Peninsula.C.antiquata,a commercially important clam in aquaculture,is one of the most critically endangered species in China.It has experienced severe population declines due to habitat destruction and overfishing during the last two decades.The depletion of natural resources encouraged development of culture techniques for this species,in order to satisfy the demand of the market and maintain the wild population.However,cultivation may result in reduction of genetic diversity unless we know the genetic background of the species.Therefore it is necessary to investigate the genetic structure of this species.Molecular markers have been very useful for analysis of genetic structure.Among many types of molecular markers,we selected the ribosomal rRNA gene first internal transcribed spacer （ITS1）.It is widely used in genetic variation and phylogenetic studies of animals and plants because of its high rate of molecular evolution.In recent years,the usage of ITS1 to assess genetic variations in bivalves has increased.To study the genetic variability,five wild stocks of C.antiquata were collected from Shandong Rizhao （RZ）,Jiangsu Lianyungang （LYG） and Qidong （QD）,Fujian Changle （CL）,Guangxi Beihai （BH） in China,and the genetic variation was analyzed based on ITS1 nucleotide sequences of rDNA.PCR amplification with the primers ITS1-F and ITS1-R was performed and the PCR products were cloned and sequenced.DNA sequences were analyzed using DNAStar,and were aligned in ClustalX.The phylogenetic trees were constructed using Neighbor-Joining method （on MEGA 4

关 键 词：西施舌 ITS1 序列分析 

分 类 号：Q953[生物学—动物学] S917.4[农业科学—水产科学]