闽浙地区香鱼线粒体Cyt b基因和D-loop区序列多态性分析

对浙江瑞安、福建宁德、福建东张水库3个地理群体共31例香鱼(Plecoglossus altivelis)的线粒体细胞色素b(Cyt b)基因和线粒体D-loop区序列进行了PCR扩增、序列测定、核苷酸组成和多态性分析。Cyt b基因中, A、T、C和G 4种核苷酸的比例分别为19.72%、29.71%、32.25%和18.32%, A + T含量为49.43%, G + C含量为50.57%。D-loop区序列中, A、T、C和G 4种核苷酸的比例分别为29.99%、29.29%、23.80%和16.92%, A + T含量为59.28%, G + C含量为40.72%。在长度为1 141 bp的Cyt b基因序列中, 仅存在1个变异位点, 核苷酸多样性指数(π值)为0.00028, 31个样本中仅出现两种单倍型; 857 bp长的D-loop区序列中, 仅存在5个变异位点, 核苷酸多样性指数(π值)为0.00199, 仅出现5种单倍型。这表明闽浙地区香鱼的遗传多样性水平很低, 应当加大对香鱼的保护力度。

Polymorphisms of mitochondrial Cyt b gene and D-loop region in sweetfish (Plecoglossus altivelis Temminck et Schlegel) from Zhejiang and Fujian Provinces

We reported here the molecular analysis of mitochondrial genomes in sweetfish (Plecoglossus altivelis). Thirty-one specimens were recruited from Ruian, Zhejiang Province, Ningde, Fujian Province, and Dongzhang reservoir, Fujian Province. DNA segments spanning cytochrome b gene and D-loop region derived from these specimens were PCR-amplified and subsequently characterized by direct DNA sequence analysis. The resultant sequence data were com-pared with the consensus sequence and further analyzed for proportion of each nucleotide. The average A, T, C, and G con-tents in Cyt b gene were 19.72%, 29.71%, 32.25%, and 18.32%, respectively, while the contents of A+T and G+C were 49.43% and 50.57%. In the D-loop region, the average A, T, C and G contents were 29.99%, 29.29%, 23.80%, and 16.92% and the contents of A+T and G+C were 59.28% and 40.72%, respectively. There was only one variant in the Cyt b gene belong to two haplotypes and the nucleotide diversity (pi) was merely 0.00028. In the D-loop region, there were only 5 po-lymorphic sites belonging to 5 haplotypes and its nucleotide diversity (pi) was only 0.00199. These results showed that the genetic diversity of P. altivelis from these regions was very low.