Population structure of Anopheles gambiae in Africa
Population structure of Anopheles gambiae in Africa
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DOI：
10.1093/jhered/esg024
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发表时间：
2003-03-01
影响因子：
3.1
通讯作者：
Hawley, WA
中科院分区：
文献类型：
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作者：
Lehmann, T;Licht, M;Hawley, WA
利用11个微卫星位点对来自10个国家的16个样本的冈比亚按蚊种群结构进行了研究。所有基因座都位于多态倒位之外。检测到基因座间的杂合性，并从旨在捕获全基因组模式的分析中删除了两个推定的离群基因座。基因库的两个主要部分被高分化（F-ST > 0.1）分开。西北区包括来自塞内加尔、加纳、尼日利亚、喀麦隆、加蓬、刚果民主共和国和肯尼亚西部的种群。东南部（SE）包括来自肯尼亚东部，坦桑尼亚，马拉维和赞比亚的人口。对A.沿着裂谷的冈比亚部分地将这些地区分开。减少遗传多样性在SE司和私人等位基因的基础上的分析结果支持的假设，最近的瓶颈，其次是殖民化从西北人口塑造了这种结构。在NW区，具有M rDNA基因型的群体似乎形成了一个单系分支。尽管遗传距离随着地理距离的增加而增加，但某些群体之间存在不连续性。刚果民主共和国同域分布的M和S群体之间不存在杂合子，基因座678的高分化（F-ST > 0.28）与所有其他基因座的低分化（-0.02 < F-ST < 0.09）形成对比，并与刚果民主共和国每种形式中Hardy-Weinberg预期的持续偏离形成对比。无论是最近的生殖隔离或选择单独不能解释这些结果，这种情况是兼容的初期物种形成。由于分子形式在疟疾传播中可能发挥不同的作用，未来的研究应将其分开处理。
The population structure of Anopheles gambiae in Africa was studied using 11 microsatellite loci in 16 samples from 10 countries. All loci are located outside polymorphic inversions. Heterogeneity among loci was detected and two putative outlier loci were removed from analyses aimed at capturing genome-wide patterns. Two main divisions of the gene pool were separated by high differentiation (F-ST > 0.1). The northwestern (NW) division included populations from Senegal, Ghana, Nigeria, Cameroon, Gabon, Democratic Republic of Congo (DRC), and western Kenya. The southeastern (SE) division included populations from eastern Kenya, Tanzania, Malawi, and Zambia. Inhospitable environments for A. gambiae along the Rift Valley partly separate these divisions. Reduced genetic diversity in the SE division and results of an analysis based on private alleles support the hypothesis that a recent bottleneck, followed by colonization from the NW populations shaped this structure. In the NW division, populations possessing the M rDNA genotype appeared to form a monophyletic clade. Although genetic distance increased with geographic distance, discontinuities were suggested between certain sets of populations. The absence of heterozygotes between sympatric M and S populations in the DRC and the high differentiation in locus 678 (F-ST > 0.28) contrasted with low differentiation in all other loci (-0.02 < F-ST < 0.09) and with the persistence of departures from Hardy-Weinberg expectations within each form in the DRC. Neither recent reproductive isolation alone nor selection alone can explain these results, a situation that is compatible with incipient speciation. Because it is possible that the molecular forms play different roles in malaria transmission, future studies should treat them separately.