我国辽宁省嗜人按蚊群体与其它分布地群体的遗传分化研究

STUDY ON POPULATION GENETIC DIVERGENCE OF ANOPHELES ANTHROPOPHAGUS BETWEEN LIAONING AND OTHER DISTRIBUTIONS IN CHINA

目的 研究我国辽宁省嗜人按蚊群体与其他分布地群体的遗传分化现象。 方法 应用 RAPD- PCR技术研究我国辽宁、四川和河南 3省 5个代表点的嗜人按蚊自然群体和江苏省实验室群体共 5 2个样本的遗传多态现象 ,依据 5 9个 RAPD等位基因座进行分析。 结果 嗜人按蚊群体的多态位点比例为 4 5 .8%～ 71.2 % ,平均 6 1.5 8% ,期望杂合度为 0 .16 3～ 0 .2 5 6 ,平均 0 .2 2 4 ;分别用 Wright(Fst)、L ynch和 Milligan(Fst)、Weir和 Cockerham (θ)的方法计算固定指数 ,平均值分别为 0 .2 2 4、0 .198和 0 .2 81,其相应的 N m分别为 0 .9、1.0和 0 .6 ,可见嗜人按蚊的基因流水平极低 ,致使群体产生了分化 ;嗜人按蚊各群体间的遗传差异性为 0 .0 2 87～ 0 .1397,属种内变异 ;聚类图显示 ,辽宁省的 3个群体与其他群体分为两枝。

Objective To determine whether Anopheles anthropophagus has genetic divergence between Liaoning and other distribution populations. Methods Fifty two samples of An. anthropophagus from five natural populations in Liaoning Province, Henan Province, Sichuan Province and one laboratory colony in Jiangsu Province were studied on genetic polymorphism using RAPD PCR. Fifty nine RAPD allelic loci were analyzed. Results The percentage of polymorphic sites were 45.8%～71.2%, with average of 61.58%. The range of expected mean heterozygosity was from 0.163 to 0.256, with average of 0.224. These data suggested there was considerable genetic polymorphism in the populations of An. anthropophagus . The averages of Fst and θ calculated by Wright, Lynch and Milligan, Weir and Cockerham measures were 0.224, 0.198 and 0.281, with corresponding migrating rate of 0.9, 1.0 and 0.6, respectively. They indicated that the level of gene flow was very low, which conduced to differentiation among populations. The genetic diversities among populations of An. anthropophagus were 0.0287～0.1397 that implied intraspecific variation. Cluster analysis revealed that the three populations in Liaoning Province were separated from the other populations. Conclusion An. anthropophagus population in Liaoning Province had divided from the other populations.