基于线粒体Cyt b基因的皖南山区温州光唇鱼种群遗传结构

Population Genetic Structure of Acrossocheilus wenchowensis in Mountainous Area of Southern Anhui Province Based on Mitochondrial Cyt b gene

为探讨皖南山区温州光唇鱼的种群遗传结构,采用线粒体细胞色素b基因(Cyt b)对该区5个野生种群(祁门、黟县、休宁、旌德和宁国)进行群体遗传变异分析。131个样本的Cyt b基因(1141 bp)中共检出38个变异位点(变异率3.33%)、14种单倍型。序列碱基的平均含量分别为A(28.2%)、C(29.7%)、T(27.0%)、G(15.1%),A+T含量(55.2%)明显大于G+C含量(44.8%)。5个地理种群的单倍型多样性(0.0000~0.6799)和核苷酸多样性(0.0000~0.00759)普遍较低。群体分化系数(FST:0.2916-0.9782)和AMOVA分析中高达52.74%的遗传变异来自地理种群间,说明温州光唇鱼地理种群间已产生显著遗传分化;但不同水系的种群间没有显著遗传差异。群体间系统进化树显示:5个群体聚为两大进化枝,祁门和旌德种群为一枝,其余种群为另一枝。温州光唇鱼的这种种群遗传结构与地理隔离及其生态习性相关。

In order to study the population genetic structure of Acrossocheilus wenchowensis in mountainous area of southern Anhui Province, mitochondrial cytochrome b （Cyt b） gene from 5 populations （Qimen, Yixian, Xiuning, Jingde and Ningguo） with 131 individuals of A. wenchowensis were amplified and sequenced bi- directionally. Finally 14 haplotypes were identified and 38 mutation sites were detected. The average contents ofT, C, A and G were 27.0%, 29.7%, 28.2% and 15.1% respectively, A＋T content （55.2%） was higher than G＋ C content （44.8%）. The haplotype diversity （0.0000-0.6799） and nucleotide diversity （0.0000-0.00759） of the 5 populations were all low. The genetic differentiation index （Fsr） of populations ranged from 0.2916 to 0.9782. Analysis of molecular variance （AMOVA） indicated that there was 52.74% of variance among populations, suggesting that populations had significant genetic differentiation. But there was no obvious genetic difference among populations from different rivers. The molecular phylogenetic tree （N J-tree） showed that the 5 populations could be divided into two groups, with Qimen and Jingde populations clustered into group 1 and the other three populations clustered into group 2. The results were related to geographic isolation and ecological habit of A. wenchowensis.