湖州河川沙塘鳢群体线粒体DNA cyt b基因序列的遗传多样性分析

Genetic Diversity Analysis of Mitochondrial DNA cyt b Gene Sequence of Odontobutis potamophila Population in Huzhou

河川沙塘鳢具有肉鲜味美,细嫩可口的特点,营养价值与经济价值颇高,是一种极具发展潜力的水产养殖品种,对野生和人工繁育河川沙塘鳢的遗传结构进行检测分析,可为选育和种质保护提供参考资料。本文对湖州河川沙塘鳢(钟管野生群体及八里店养殖群体)的线粒体细胞色素b(cyt b)基因全长进行扩增和测序,并应用生物信息学软件与Gen Bank中太湖、鄱阳湖和巢湖3个群体的数据进行比较。河川沙塘鳢cyt b基因全长1141 bp,4种碱基在所得序列中平均含量为A(26.8%)、G(13.8%)、T(28.0%)、C(31.4%),序列分析显示,cyt b基因序列中变异位点378个,占分析位点的44.26%,含有241个简约信息位点,平均转颠换比值(TS/TV)为0.76。在5个群体138个个体中共检测到75个单倍型,平均单倍型多样性为0.869~1.000,核苷酸多样性为0.01431~0.03848。各群体间遗传距离差异较大(0.01493~0.05868),其中八里店与钟管群体的遗传距离最小(0.01493),而鄱阳湖与巢湖群体的遗传距离最大(0.05868),与构建的聚类图分析结果一致。群体中性检验显示八里店、钟管和太湖的Tajima’s D和Fu’s Fs值为正值;鄱阳湖和巢湖群体为负值,5个群体Tajima’s D和Fu’s Fs检验均不显著(P>0.01)。总体上,5个群体间具有较高程度的遗传分化。除了湖州的八里店与钟管群体共享6种单倍型外,其他群体间基本不共享单倍型,这可能是八里店养殖群体亲本来源于钟管野生群体的原因。应用cyt b基因可以明确地将湖州、太湖、鄱阳湖和巢湖群体之间区分开来。

Odontobutis potamophila is an aquaculture species with great development potential, due to its characteristic of delicious meat with high nutritional and economic value. In order to provide reference information for breeding and germplasm protection, it is necessary to detect and analyze the genetic structure of wild and artificial population of Odontobutis potamophila. In this experiment,the sequence of full-length mitochondrial cytochrome b gene was amplified with samples from Zhongguan wild population and Balidian artificial population in Huzhou and compared with the sequence data of Taihu Lake, Poyang Lake, and Chaohu Lake in GenBank by using bioinformatics softwares. The results showed that the full length of cyt b gene in detected samples was 1 141 bp. Sequence analysis showed that the average content in four kinds of bases in cyt b gene sequences, were A(26.8%), G(13.8%), T(28.0%), C(31.4%). cyt b sequence performed with A’s and T’s preferences and strong anti G bias. Moreover, there were 378 mutation sites, accounting for 44.26% of the analysis sites. The number of parsimony-informative sites was 241. The average of transversion ratio(TS/TV)was 0.76. Furthermore, a total of 75 haplotypes were detected in 138 individuals from 5 populations. The average haplotype diversity and the nucleotide diversity were 0.869~1.000 and 0.01431~0.03848, respectively. Moreover, there was a large genetic distance gap among each population in the genetic distance, about 0.01493~0.05868. Among them, Balidian and Zhongguan population had the closest genetic distance. The furthest genetic distance existed between Poyang Lake and Chaohu Lake population, which was consistent with the results of cluster map analysis. Furthermore, the neutrality test indicated that the test was not significant in the five populations(P>0.01). Tajima’s D and Fu’s Fs values were positive in Balidian, Zhongguan and Taihu Lake but negative in Poyang Lake and Chaohu Lake populations. In general, there was a high degree of genetic differentiation among the five populations. Balidian and Zhongguan population in Huzhou had the same six haplotypes, which could be due to the Balidian population’s parents derived from the Zhongguan population. However, there were no haplotype shared among other populations. cyt b gene could be used to distinguish the Huzhou, Taihu Lake, Poyang Lake and Chaohu Lake populations.