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利用线粒体细胞色素c氧化酶Ⅰ亚基(COⅠ)序列研究了南海海区鲻鱼群体的遗传多样性水平和遗传结构。通过PCR扩增与序列测定获得了长度为621bp的基因片段。在35个样品中共发现47处碱基变异,A、T、G、C碱基的平均含量分别为31.6%、24.1%、25.0%和19.2%。35条COⅠ序列共定义了25个单倍型,存在47个多态性位点,产生49个突变。其中,简约信息位点有36个,占总位点数的5.8%,同义替换位点7个,占总变异位点的14.9%,没有发现插入或缺失现象。单倍型多样性(Hd)为0.9563,核苷酸多样性(Pi)为0.02795,平均碱基差异(K)为17.36。Tajima’sD中性检验结果为1.29916,但差异不显著(P>0.10)。采用邻接法(NJ)和非加权配对算术平均法(UPGMA)构建分子系统树,所有的25个单倍型被分成两个分支。结果表明,南海海区鲻鱼种群具有较高的遗传多样性水平。其结果可以为合理开发和利用鲻鱼野生资源,以及建立和保护鲻鱼种质资源提供必要的参考。
The mitochondrial cytochrome c oxidase Ⅰ subunit (COⅠ) sequence was used to study the genetic diversity and genetic structure of anchovy in the South China Sea. A 621bp gene fragment was obtained by PCR amplification and sequencing. A total of 47 nucleotide variations were found in 35 samples. The average contents of A, T, G and C bases were 31.6%, 24.1%, 25.0% and 19.2%, respectively. Twenty-five haplotypes were defined by 35 COⅠ sequences, and 47 polymorphic sites were found, resulting in 49 mutations. Among them, there were 36 parsimony informative sites, accounting for 5.8% of the total number of sites and 7 synonymous substitution sites, accounting for 14.9% of the total mutated sites. No insertion or deletion was found. The haplotype diversity (Hd) was 0.9563, the nucleotide diversity (Pi) was 0.02795, and the average base difference (K) was 17.36. The Tajima’sD neutrality test was 1.29916, but the difference was not significant (P> 0.10). The phylogenetic tree was constructed using Neighbor-Joining (NJ) and Unweighted Pairwise Arithmetic Average (UPGMA), all 25 haplotypes being split into two arms. The results showed that the marine fish stocks in the South China Sea had a high level of genetic diversity. The results can provide the necessary reference for the rational development and utilization of the wild catfish resources, as well as the establishment and protection of catfish germplasm resources.