Population genetic structure of Plasmodium falciparum in the two main African vectors, Anopheles gambiale and Anopheles funestus
Population genetic structure of Plasmodium falciparum in the two main African vectors, Anopheles gambiale and Anopheles funestus
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DOI：
10.1073/pnas.0702715104
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发表时间：
2007-05-08
影响因子：
11.1
通讯作者：
Renaud, Francois
中科院分区：
文献类型：
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作者：
Annan, Zeinab;Durand, Patrick;Renaud, Francois
我们研究了恶性疟原虫与其两种主要非洲媒介冈比亚按蚊和funestanopheles相关的遗传多样性模式。我们从三个热带地点解剖了10296只野生捕获的蚊子，两个在喀麦隆（Simbock和Tibati，相隔320公里），一个在肯尼亚（Rota，距离另外两个地点大约2000公里）。我们检测了183只感染蚊子肠道的746个卵囊的7个微卫星位点。从两种病媒中分离得到的寄生虫具有很高的遗传多态性。两种的期望杂合度（H-E）均为0.79；观察到的杂合度（H-O）分别为0.32和0.42，表明两种病媒间存在相当程度的近交。相同配子间的平均自交(s)为s = 0.33。近交率在不同地点和两种媒介种之间的差异无统计学意义。正如预期的那样，由于近交率高，连锁不平衡非常严重；冈比亚田鼠的21对基因座和非洲田鼠的21对基因座中有15对基因座具有显著性，尽管在同一染色体上的基因座之间只有2个两两比较。总体而言，根据F统计评估，恶性疟原虫的遗传种群结构主要是克隆型而非泛型，这种种群结构有利于抗疟药物的传播和疫苗耐药性，从而可能损害疟疾控制工作的有效性。
We investigated patterns of genetic diversity of Plasmodium falciparum associated with its two main African vectors: Anopheles gambiae and Anopheles funestus. We dissected 10,296 wild-caught mosquitoes from three tropical sites, two in Cameroon (Simbock and Tibati, separated by 320 km) and one in Kenya (Rota, > 2,000 km from the other two sites). We assayed seven microsatellite loci in 746 oocysts from 183 infected mosquito guts. Genetic polymorphism was very high in parasites isolated from both vector species. The expected heterozygosity (H-E) was 0.79 in both species; the observed heterozygosities (H-O) were 0.32 in A. funestus and 0.42 in A. gambiae, indicating considerable inbreeding within both vector species. Mean selfing (s) between genetically identical gametes was s = 0.33. Differences in the rate of inbreeding were statistically insignificant among sites and between the two vector species. As expected, because of the high rate of inbreeding, linkage disequilibrium was very high; it was significant for all 21 loci pairs in A. gambiae and for 15 of 21 pairs in A. funestus, although only two pairwise comparisons were between loci on the same chromosome. Overall, the genetic population structure of A falciparum, as evaluated by F statistics, was predominantly clonal rather than panmictic, a population structure that facilitates the spread of antimalarial drug and vaccine resistance and thus may impair the effectiveness of malaria control efforts.