大鳞副泥鳅7个群体遗传变异的微卫星分析

Microsatellite DNA Analysis on Genetic Diversity of Seven Populations of Paramisgurnus dabryanus

利用泥鳅(Misgurnus anguillicaudatus)的微卫星引物跨种扩增大鳞副泥鳅(Paramisgurnus dabryanus),通过家系扩增、PCR产物测序筛选出6个座位,用于大鳞副泥鳅7个野生群体的遗传结构分析。结果显示,群体的平均等位基因数在3.167～4.833,平均观测杂合度(Ho)在0.248～0.417,平均期望杂合度(He)在0.379～0.505,多个座位存在零等位基因、杂合子缺失现象,显示大鳞副泥鳅种群遗传多样性较低。采用UPGMA法对7个群体基于DA遗传距离进行聚类,可分为4类,位于长江中下游的沙市、澧县、武汉、鄱阳湖群体先聚为一类,后与石首群体聚类,最后与珠江水系的广州群体聚类,而位于长江上游的泸州群体则单独聚为一类。群体的F-统计量(Fst)为0.2987,表明群体间存在显著的遗传分化,主要由泸州群体与其它地区群体间的遗传分化引起。

By using the microsatellite primers of pond loach Misgurnus anguillcaudatus to perform cross-species am- plification of Paramisgurnus dabryanus, family amplification and PCR product sequencing, six loci were screened out to be suitable to the analyses of genetic diversity and population structure of seven wild populations of P. dabry- anus. The average number of alleles, observed heterozygosity （11o） and expected heterozygosity （He ） ranged from 3. 167 to 4. 833, 0. 248 to 0. 417 and 0. 379 to 0. 505, respectively. These results showed that Null alleles and ap- parent deficiency of heterozygotes were deteeted at some loci, and the level of genetic diversity in P. dabryanus was relatively low. The cluster analysis by UPGMA method was carried out based on the DA genetic distance of seven populations. The results showed that all populations comprised four groups ： the separate Luzhou population （ in the upper reaches of the Yangtze）, the clustering population of Guangzhou （in the Zhujiang water system）, the Sh- ishou population, and Poyanghu population （including that of Shashi, Lixian, Wuhan, in the middle and lower reaches of the Yangtze River）. The value of the F-statistics was 0. 2987 and this suggested that P. dabryanus ex- hibited a significant genetic differentiation, mostly resulting from genetic differentiation of Luzhou and the other six populations.