东海带鱼DNA条形码的建立及COⅠ序列变异分析

DNA Barcoding Construction and Genetic Diversity Revealed by mtDNA COⅠ of Trichiurus lepturus in the East China Sea

采用聚合酶链反应(PCR)技术对浙江近海水域带鱼群体(n=15)的mtDNA COⅠ基因序列进行扩增,获得了大小约为650 bp的扩增产物。对PCR产物进行双向测序,得到了609 bp的基因片段(除去两端的部分序列),获得了带鱼的DNA条形编码。用DNAMAN软件进行了排序比较发现,东海带鱼的COⅠ基因序列同源性高达99.69%;用DNASP软件分析得知,15个序列共有10个单倍型(在GenBank登录号:GU970070-GU970075,GU970079-GU970082),在15个个体中,共检测到13个变异位点,包括11个转换和2个颠换位点。运用MEGA软件计算出了不同个体间的遗传距离,并据此构建了UPGMA和NJ系统树。用DNASP软件计算出的多态位点数为13、核苷酸多样性指数和平均核苷酸差异数分别为0.005 13和3.124。研究结果表明,东海带鱼的COI基因个体变异程度比较小,对研究带鱼的种群结构和不同地理种群的遗传分化具有一定的应用价值。

The PCR technique was used to amplify the mtDNA CO I gene in 15 individuals of Trichiurus lepturus collected from the East China Sea, along the offing sea area of Zhejiang. The PCR products were se- quenced and about 650 bp of CO I gene were obtained. Remove partial sequences of the two ends 609 bp se- quences were obtained, regarding as the DNA Barcoding of T. lepturus. By using DNAMAN to align and compare the sequences of these 15 individuals with each other, the identity of CO I pairwise sequences was 99.69 % and by using DNASP to analyze the genetic diversity, the result showed that there were 10 haplotypes（GenBank accession no. GU970070-GU970075, GU970079-GU970082） and 13 variation sites were observed, of which there were 11 transition sites and 2 transversion sites, the number of polymorphic sites, the nucleotide diversityand the average number of nucleotide defferences were calculated simultaneous and the results were 13, 0.005 13 and 3.124, respectively. The pairwise genetic distances were computed by MEGA. The UPGMA and NJ phylogenetic trees were obtained through the cluster analysis over the pairwise genetic distance. All the results showed that the genetic diversity in CO I gene of T. lepturus in the East China Sea was relatively low and proviede a basic molecular biology clue to the studies on population genetics and CO I gene can be one of the genetic markers available for studing groups structure.