浙江三门湾日本蟳群体线粒体16Sr RNA基因序列多态性

采用聚合酶链式反应(PCR)技术对浙江三门野生日本蟳20个个体的mtDNA 16SrRNA基因进行扩增,PCR产物经纯化后进行测序,得到495 bp的核苷酸序列片段。测序结果经比对校正后,获得三群体16SrRNA基因一致序列,片断长为495 bp,其中变异位点15个,简约位点11个,总变异为3.03%。在测得的495 bp目的DNA片段中,碱基T、C、A、G平均组成分别为35.2%、17.9%、35.3%和11.6%,其A+T含量(70.5%)远高于G+C含量(29.5%)。在20个个体中共检测到7个单倍型,单倍型多样性为0.642,核苷酸多样性为0.448%。根据Kimura遗传距离的计算结果,各单倍型之间的遗传距离为0.2%~2.68%。16SrRNA构建的NJ系统发育树表明,梭子蟹属的远洋梭子蟹和青蟹属的拟穴青蟹亲缘关系较近,与蟳属的日本蟳亲缘关系较远,与形态和RAPD研究结果一致。

Polymorphism of mtDNA 16SrRNA gene sequence in Charybdis japonica of Sanmen Gulf, Zhejiang Province

Polymerase chain reaction(PCR) technique has been used to amplify the mtDNA 16SrRNA gene from 20 wild individuals of Charybdis japonica caught from Sanmen Gulf,Zhejiang Province.The PCR products were purified and sequenced.After aligned,495 bp sequences of 16SrRNA gene has been obtained and analyzed.15 polymorphic sites and 7 haplotypes were detected from the partial 16SrRNA sequences.The average nucleotide composition of T,C,A,G were 35.2%,17.9%,35.3% and 11.6% respectively.The haplotype diversity(H) was 0.642 and the nucleotide diversity(π) was 0.448%.The genetic distances between haplotypes were from 0.2% to 2.68% calculated by Kimura's method.The phylogenetic tree based on 16SrRNA gene sequences showed the close relationship between Portunus pelagicus and Scylla paramamosain was more than that between the above two species and Charybdis japonica,which was consistent with the conclusions based on morphologic and RAPD methods.