广西钦州湾牡蛎线粒体COI基因片段变异分析

采用PCR方法扩增66个广西钦州湾牡蛎个体的线粒体细胞色素氧化酶I亚基基因(COI)片段,纯化后经测序分析,得到535 bp的碱基序列,其中A、T、G、C、A T和C G含量分别为23.8%、37.5%、20.5%、18.2%、60.5%和39.5%。比较它们与香港牡蛎和有明巨牡蛎COI序列的差异,钦州湾白肉牡蛎与香港牡蛎COI序列完全相同,而红肉牡蛎与有明巨牡蛎序列相同。DNAStar软件对比分析发现30个突变位点,其中16个位点为转换,14个位点为颠换。MEGA4软件构建NJ系统进化树显示白肉牡蛎和红肉牡蛎分为不同的2支。据此初步认为广西钦州湾牡蛎可能为2个不同的种群,COI基因片段可作为分析牡蛎种群遗传和系统发育的分子标记。

Genetic diversity of Crassostrea from Qinzhou gulf in Guangxi using mitochondrial COI gene fragment sequence analysis

After mitochondrial COI gene fragment of 66 Qinzhou gulf oysters of Guangxi were amplified via PCR,purified,535bp nucleotide sequences were retrieved.The content of A,T,G,C A T and C G in the fragment were 23.8%,37.5%,20.5% and 18.2% respectively,The sequence comparison was made among C.hongkongsis and C.ariakensis with them,Qinzhou gulf white meat oyster had the same nucleotide sequence with C.hongkongsis,while red meat oyster had the same nucleotide sequence with C.ariakensis.Nucleotide variation sites number between the two species was 30 by DNAStar,in which 16 were transitions and 14 were transversions.NJ phylogenetic tree was obtained by MEGA4,which showed that white meat oyster and red meat oyster were different branch.It was induced that Qinzhou gulf oyster may be two different species from Guangxi province.Mitochondrial COI gene fragment was suitable to be used as molecular marker for related studies,such as the analyses of oyster population genetics and construction phylogeny.