微卫星锚定PCR技术研究云南微小按蚊群体遗传结构

目的研究云南不同地理来源微小按蚊的群体遗传结构,探讨不同群体间的遗传结构和分化现象。方法在云南省东、西、南、北及中部各选择1～2个自然村,用紫外诱蚊灯于每晚17时至次日7时诱蚊,收集雌成蚊以氯仿麻醉,经形态学鉴别为微小按蚊的样本取单蚊蚊腿,再经复合PCR方法鉴别微小按蚊A或C。采用微卫星锚定PCR技术（SSR-PCR）扩增微小按蚊单蚊基因组DNA,用BIOSIS,RAPDFST,RAPDDIST及PHILIP等软件统计分析基因位点多态性、固定指数FST及θ、种群间的迁移率（Nm）以及遗传距离、聚类分析构建系统树。结果以多态位点比例衡量各种群的遗传多态性,云南不同地区微小按蚊均共享较高多态性,其中元江（C）的变异程度较低,为43.3%,潞西（A）的变异程度较高,为78.6%。FST和θ结果提示,微小按蚊的遗传变异主要存在于种群内部。微小按蚊A与C分别或两者合并分析,Nm均大于1。系统树主要分为两支,元阳（C）、大关（C）和勐腊（C）聚为一支;另一支分为元江（C）与潞西（A）,新平（A）和临沧（C）,以及勐腊（A）共3层。结论各群体间遗传距离部分与亲缘种分类有关,未发现与地理距离相关。

Population Genetics Study on Anopheles minimus in Yunnan Province by SSR-PCR

Objective To study the genetic variations of Anopheles minimus in Yunnan Province. Method An.minimus samples were collected from the villages of Yunnan Province. Muhiplex-PCR and morphological examination were used for species identification. PCR products were obtained by SSR-PCR. BIOSIS, RAPDFST, RAPDDIST, PHILIP were used for calculation and analysis of the population diversity, FST, 0, Nm and genetic distance of each population, then dendrogram was constructed. Result A high level of genetic diversity in An. minimus was observed. The genetic variation in An.minimus C in Yuanjiang was lowest （43.3%）, and was highest in An.minimus A （78.6%） in Luxi. According to the values of FST and 0, the genetic variation was mainly inside the population itself. In the analysis of gene flow among An.minimus A and C, the value of Nm was smaller than 1. Phylogenetic analysis revealed that the eight populations of An.minimus can be classified into two divisions, namely the An.minimus C in Daguan, Yuanyang and Mengla, and An.minimus C in Yuanjiang, An.minimus A in Luxi, An. minimus C in Lincang, An.minimus A in Xinping, and An.minimus A in Mengla. Conclusion The genetic distance and classification of An.minimus was established. The genetic variation is not correlated with the geographical distribution of the species.