不同地理群体的鲇线粒体DNAND1基因序列比较分析

Comoarative Analysis on Mitochondrial DNA ND1 Gene Sequence of Five Wild Silurus asotus Populations

为了对长江中上游主要支流鲇5个野生群体——雅砻江群体(YLJ)、岷江群体(MJ)、金沙江群体(CS)、乌江群体(WJ)、氵舞阳河群体(WYH)的遗传变异进行分析,对27个样品的ND1基因进行PCR扩增,并将PCR产物进行测序;用CLUSTALXv1.81软件对所得的27个ND1序列进行比对;通过Dna SP5.10软件、Tajima’s D和Fst分析对所得的ND1序列进行比较分析,并构建分子系统树。结果表明:共检测出105个变异位点,8种单倍型。雅砻江、岷江、金沙江、乌江、氵舞阳河5个野生群体的单倍型多样性(H)分别为0.400、0.600、0.667、0.857、0.400,核苷酸多样性(π)分别为0.000 82、0.000 62、0.044 44、0.044 36、0.000 41。雅砻江、氵舞阳河2群体存在负向选择或种群扩张,其余群体符合中性进化模型,且有一些单倍型的分化,只有金沙江群体的遗传差异显著,群体间分子变异不显著。结论:雅砻江、岷江、金沙江、乌江群体之间的亲缘关系较近,氵舞阳河群体与其他群体间的亲缘关系较远。

The ND1 gene of 27 samples from five wild S. asotus populations （YLJ, MJ, CS, WJ and WYH） of Yangtze River middle and upper reaches was amplified by PCR and the amplification sequence was detected. 27 ND1 gene sequences were compared by CLUSTALXvl. 81 software. Finally the molecular phylogenetic tree was established based on ND1 gene sequence analyzed by Dna SP 5. 10 software, Ta]ima＇ s D and Fst. The results showed that 105 variation locuses and 8 haplotypes were determined. The haplotype diversity （H） of YLJ, MJ, CS, WJ and WYH wild S. asotus populations was 0. 400, 0. 600, 0. 667, 0. 857 and 0. 400 and the nucleotide diversity（Tr）of YIJ, MJ, CS, WJ and WYH wild S. asotus populations was 0. 000 82, 0. 000 62, 0. 044 44, 0. 044 36 and 0. 000 41 respectively. There was negative selection or population expansion in YLJ and WYH wild S. asotus populations and other wild Silurus asotus populations with some haplotype differentiation fitted the neutral evolutionary model. There was significant genetic difference in CS wild S. asotus population but there was no significant difference in molecular variance among five wild S. asotus populations. In conclusion, YLJ, MJ, CS and WJ wild S. asotus populations had the closest genetic relationship but WYH wild S. asotus population had the far genetic relationship with YLJ, MJ, CS and WJ wild S. asotus populations.