棘头梅童鱼线粒体控制区的序列变异与群体遗传结构

mtDNA control region sequence variation and genetic structure of Collichtys iucidus populations

中文关键词: 棘头梅童鱼  群体遗传结构  线粒体控制区  序列

英文关键词: Collichtys iucidus  Population genetic structure  mtDNA control region  Sequence

中文摘要:

      采用PCR扩增测序法获得了棘头梅童鱼Collichtys iucidus南通、启东、芦潮港、温州、瑞安、福州、番禺7个地理群体53尾鱼的mtDNA控制区全序列。棘头梅童鱼控制区序列长度为778~782 bp，序列长度变异主要是由位点的插入或缺失造成，识别了终止序列区TAS和保守序列区CSB1、CSB2、CSB3序列。共检测到多态位点66个，占全部序列的8.44%，检测到单倍型33种，平均单倍型多样性（Hd）为0.934 7±0.017 5，平均核苷酸多样性（π）为0.017 5±0.002 3。棘头梅童鱼群体内的遗传距离（K 2-P）为0.001 7～0.022 8，群体间的遗传距离为0.002 3～0.043 3，群体间的分化指数FST为-0.058 4～0.845 8，基因流为0.05～19.62。AMOVA分析结果显示，群体间的变异为74.21%，群体内的变异为25.79%（P<0.05），表明群体间发生了显著的遗传分化。以NJ法构建的亲缘关系树显示，棘头梅童鱼7个群体分为两个大支，一支以北方类群（南通、启东、芦潮港、温州群体）个体为主，另一支以南方类群（福州和番禹群体）个体为主，而位于南、北方类群中间位置的瑞安群体则与两大类群均有交叉。

英文摘要:

      The complete sequences of mitochondrial control region of 53 individuals of Collichtys iucidus from seven populations, Nantong(NT), Qidong(QD), Luchaogang(LC), Wenzhou(WZ), Ruian(RA), Fuzhou(FZ), and Panyu(PY) were obtained by PCR cloning . Sequence lengths of the control region of C. iucidus varied in the range of 778-782 bp, which was mainly caused by the insertion or deletion. The conserved regions, such as TAS and CSB-1,-2, and -3 were identifiable in the control regions of C. iucidus. There were 66 polymorphic sites, which accounted for 8.44% in all sequences, and 33 haplotypes were found in all individuals. The average value of haplotype diversity (Hd) was 0.934 7±0.017 5 and the average value of nucleotide diversity (π) was 0.017 5±0.002 3 for seven populations. The K2-P distance within and among seven populations were 0.001 7～0.022 8 and 0.002 3～0.043 3, respectively. The difference index (FST) ranged betweenin -0.058 4～0.845 8 and the gene flow values were within the range of 0.05～19.62 for the seven populations. AMOVA analysis revealed that the inter-population variance was 74.21% and the intra-population variance was 25.79% (P<0.05). The phylogenetic tree estimated by NJ methods indicated that the C. iucidus individuals from seven populations could be clustered as two clades: the northern clade was formed by Nantong, Qidong, Luchaogang, and Wenzhou populations, while Fuzhou and Panyu popualtions formed the southern clade, and Ruian population was mixed with the above two clades.