太湖鲢鱼mtDNA D-loop区遗传多样性

为深入研究太湖鲢鱼的种群遗传结构及进化过程,有效的保护和利用太湖鲢鱼种质资源,作者采用聚合酶链式反应(PCR)技术对太湖鲢鱼的mtDNA D-loop序列进行扩增,获得了大小约为500 bp的扩增产物.PCR产物经纯化后克隆到pMD19-T Vector进行序列鉴定测序,得到了520 bp的核苷酸片段(除去引物及部分端部序列).用CLUSTAL X(1.83)软件进行排序比较,在30个个体中,共检测到52个变异位点,包括1个碱基缺失、36个转换位点、15个颠换位点及1个转换与颠换同时存在的位点.运用MEGA软件计算出不同个体间的遗传距离,并据此构建了NJ系统树.用DNASP软件计算出的多态位点数(S)为52、核苷酸多样性(Pi)和平均核苷酸差异数(k)分别为1.24%0.35%和6.368.研究结果表明,太湖鲢鱼的mtDNAD-loop个体序列变异程度较大,遗传多样性较为丰富.

Genetic Diversity of Mitochondrial DNA D-looP Sequences of Hypophthalmichthys molitrix in Tai Lake

The PCR technique was used to amplify the mtDNA D-Loop in 30 individuals of Hypophthalmichthys molitrix collected from the Tai Lake. The PCR products were purified and cloned into pMD19-T vector and sequenced. As a result, 520 bp nucleotide sequences of partial D-Loop sequence obtained (the primer and some of the marginal sequences were excluded).By using CLUSTAL X(1.83) to align and compare the sequences of these 30 individuals with each other, 52 variation sites were observed, of which there were one deletions, 36 transition sites, 15 transversion sites and one transition-transversion sites. The pairwise genetic distances were computed by MEGA. The NJ phylogenetic trees was obtained through the cluster analysis over the pairwise genetic distance. As estimated by DNASP, the number of polymorphic sites(S) is 52; the nucleotide diversity (Pi) and the average number of nucleotide diferences (K) are 1.24%±0.35% and 6.368, respectively. It can be concluded that the variation in mtDNA D-Loop of Hypophthalmichthys molitrix in the Tai Lake is relatively rich and wealthy on genetic diversity.