基于COI基因和D-loop区部分序列比较雷州半岛东、西岸湖栖鳍虾虎鱼群体的遗传多样性

为比较分析雷州半岛东、西两岸湖栖鳍虾虎鱼(Gobiopterus lacustris)遗传差异,以COI基因和D-loop区部分序列为分子标记,获取雷州半岛湖栖鳍虾虎鱼群体COI序列44条(九龙山群体21条,高桥群体23条)、D-loop序列53条(九龙山群体25条,高桥群体28条)。基于COI基因部分序列分析结果显示:619 bp的44条序列中,统计的变异位点29个;T、C、A、G碱基组成分别为:27.8%、31.0%、23.7%、17.5%,且A+T(51.5%)高于C+G(48.5%);单倍型多样性比较,九龙山群体(0.695)高桥群体(0.324);遗传分化分析表明东、西群体分化显著(Snn=0.0.591,0.01P0.05),基因流(Nm)为5.37,遗传分化系数(Gst)为0.147,固定指数(Fst)为0.042(0.001P0.01),核苷酸差异数(Kxy)为2.547,核苷酸歧义度(Dxy)为0.004。而基于D-loop区部分序列分析结果表明:563 bp的53条序列中,变异位点133个;T、C、A、G碱基组成分别为:32.3%、14.8%、35.5%、17.4%,A+T(67.8%)明显高于C+G(32.2%);单倍型多样性与COI分析结果类似,九龙山群体(0.797)高桥群体(0.661);遗传分化分析表明东、西群体分化极显著(Snn=0.970,P0.001),Fst为0.315(P0.001),Nm值为0.55,Gst、Kxy、Dxy分别为:0.157、3.506、0.006;AMOVA分析揭示群体内变异程度高于群体间;聚类分析表明,基于COI基因与D-loop区部分序列构建的邻位链接法聚类树(NJ树)均存在按照采样点聚类的现象,但D-loop更为明显。综上,雷州半岛东、西两岸湖栖鳍虾虎鱼群体出现较为明显的分化现象。

Genetic diversity of Gobiopterus lacustris populations from western and eastern Leizhou Peninsula based on partial sequences of mitochondrial COI gene and D-loop

We compared two Gobiopterus lacustris populations collected from the eastern and western Leizhou Peninsula based on COI gene and D-loop region. The partial sequences of COI gene from 44 individuals (21 from eastern Jiulongshan population and 23 from western Gaoqiao population) and D-loop region from 53 individuals (25 from JLS and 28 from GQ) were cloned. Based on COI gene, the results were as follows: there were 29 variable sites in 619 bp COI sequences. The frequencies of T, C, A, and G were 27.8%, 31.0%, 23.7%, and 17.5%, respectively, with more A + T (51.5%) than C + G (48.5%). The haplotype diversity of Jiulongshan population (0.695) was higher than that of Gaoqiao population (0.324). Genetic differentiation analysis indicated that the eastern and western populations were differentiated significantly (Snn = 0.591, 0.01 < P < 0.05). The correlative values of Nm, Gst, Fst, Kxy, and Dxy were 5.37, 0.147, 0.042, 2.547, and 0.004, respectively. However, much more variable sites (133 bp) were observed in D-loop regions with 563 bp length. In addition, there were higher frequencies of A + T (67.8%) than COI, and the haplotype diversity of Jiulongshan population (0.797) was higher than that of Gaoqiao population (0.661). Genetic differentiation of the eastern and western populations was highly significant (Snn = 0.970, P < 0.001). The values of Nm, Gst, Fst, Kxy, and Dxy were 0.157, 0.315, 3.506, and 0.006, respectively. Analysis of molecular variance revealed that the percentage of variation within populations was higher than that among populations. Cluster analysis showed the presence of clustering phenomenon, which gathered by the collected sites of sample based on COI gene and D-loop region, but D-loops were more apparent. In summary, a significant differentiation occurred between eastern and western Leizhou Peninsula.