中国近海黑鲷线粒体DNA控制区序列多态性分析

Polymorphism study of the mitochondrial DNA D-loop control region sequences from black porgy Acanthopagrus schlegeli,in the costal waters of China

采用聚合酶链式反应(PCR)和直接测序的方法,测定了广西北海、广东深圳和山东青岛3个地理群体共72尾黑鲷(Acanthopagrusschlegeli)线粒体Dloop第一高变区5′端547～549bp序列,以探讨黑鲷种群的遗传变异。分析结果表明:72条序列T、C、A、G4种核苷酸的平均含量分别为30.8%、21.8%、36.3%、11.0%。共检测到55个变异位点,其中转换位点32个,颠换位点19个,缺失/颠换位点1个,插入/颠换位点3个。72个个体具有51种单倍型(haplotype),单倍型比率为70.8%,黑鲷线粒体Dloop控制区表现出较为丰富的核苷酸多态性。对其所有单倍型依据序列距离使用NJ法构建的亲缘关系树并无明显的系谱分支,没有显示出明显的地理分布族群,说明黑鲷线粒体DNA控制区第一高变区序列无法用于黑鲷种群的鉴别。

For inquiring into the genteic diyersity and genetic structure of black porgy Acanthopagrus schlegeli, We used polymerase chain reaction （PCR） and direct nucleotide sequencing to analyze the 547 - 549 bp 5＇end of the D-loop region from 72 A. schlegeli samples, which captured from Beihai （ Guangxi province ）, Shenzhen （ Guangdong province） and Qingdao （ Shandong province ） . The results show that the A, T, G and C mean contents in those fragments were 30. 8% , 21.8% , 36. 3% , 11.0%, respectively. There were 55 variable nucleotide positions in those gene fragments, which included 38 transition sites and 13 transvertion sites, 1 insert/ transvertion site and 3 deletion/trasvertion. Comparisons of these 72 partial D-loop sequences revealed 51 mitochondrial haplotypes in A. schlegeli, the haplotype rate was 70. 8%. Those indicated that there were rich nucleotide variational polymorphism exited in A. schlegeli. Phylogenetic trees of haplotypes were constructed by NJ method. Neither significant genealogical branches nor geographic cluster were found. It showed that mitochondrial DNA highly variable region sequence is unsuitable to be used as a genetic marker for population identification.