魁蚶(Scapharca broughtonii)不同地理群体的遗传多样性及种群结构

Genetic Diversity and Geographic Population Structures of Scapharca broughtonii

中文关键词: 魁蚶  COⅠ基因  12S rRNA基因  18S rRNA基因  28S rRNA基因  遗传多样性

英文关键词: Scapharca broughtonii  COⅠ gene  12S rRNA gene  18S rRNA gene  28S rRNA gene  Genetic diversity

中文摘要:

      采用PCR技术扩增了中国山东胶南、长岛、蓬莱、荣成和韩国统营5个地理群体魁蚶(Scapharca broughtonii)样本的COⅠ、12S rRNA、18S rRNA和28S rRNA基因部分序列，分析了魁蚶5个地理群体的遗传多样性和系统进化关系。经测序拼接、剪接后，分别获得67条776 bp的COⅠ序列、72条443 bp的12S rRNA序列、75条909 bp的18S rRNA序列和75条894 bp的28S rRNA序列。序列分析结果显示，5个群体75个个体的COⅠ序列中共检测到466个多态位点，32种单倍型，单倍型多样性指数为0.925，核苷酸多样性指数为0.086；12S rRNA序列中共检测到292个多态位点，43种单倍型，单倍型多样性指数是0.928，而核苷酸多样性为0.0856；在18S rRNA序列中，5个群体都表现出丰富的遗传多样性，共有74种单倍型，909个多态位点，单倍型多样性指数为1.0，核苷酸多样性指数为0.717，其中胶南群体变异位点最多、多样性最丰富；通过对28S rRNA部分序列的分析发现，75个个体共检测到27个多态位点，18种单倍型，单倍型多样性指数为0.778，核苷酸多样性指数为0.289，蓬莱群体多样性最丰富。遗传距离分析结果表明，韩国群体与其他4个群体的遗传距离较大；基于COⅠ序列的系统进化树显示有多个聚群。

英文摘要:

      In this study we applied PCR to amplify and analyze partial sequences of mitochondrial COⅠ, 12S rRNA and ribosome 18S rRNA, 28S rRNA of five groups of Scapharca broughtonii (Jiaonan, Rongcheng, Changdao, Penglai in Shandong Province of China, and Tongyeong of Korea). In spite of the apparent genetic variation in COⅠ, 12S, 18S and 28S, the base compositions of these genes were stable. The genetic diversity of the five populations indicated the good condition of the germplasm resource of these species. Sixty-seven sequences of COⅠ, 73 sequences of 12S, 75 sequences of 18S rRNA and 75 sequences of 28S rRNA were obtained, and their lengths were 776 bp, 443 bp, 909 bp and 894 bp respectively. Sequence analysis showed that the polymorphic sites, haplotype, Hd dversity and nucleotide diversity index of COⅠ were 466, 32, 0.925 and 0.086, respectively. While that of 12S were 292, 43, 0.928, 0.0856, and 18S were 909, 74, 1.0, 0.717, and 28S were 27, 18, 0.778, 0.289. In addition, the Jiaonan population and Penglai population showed the highest diversity in 18S and 28S. Genetic distance data revealed the Korea population has bigger genetic distance with China population than that of within populations from China. Clustering analysis based on the partial sequences of COⅠ gene showed that the China S. broughtonii individuals from same population China clustered generally together, however, the Korea individuals clustered more than one group.