Distinctly different sex ratios in African and European populations of Drosophila melanogaster inferred from chromosomewide single nucleotide polymorphism data
Distinctly different sex ratios in African and European populations of Drosophila melanogaster inferred from chromosomewide single nucleotide polymorphism data
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DOI：
10.1534/genetics.107.074922
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发表时间：
2007-09-01
期刊：
影响因子：
3.3
通讯作者：
Stephan, Wolfgang
中科院分区：
文献类型：
--
作者：
Hutter, Stephan;Li, Haipeng;Stephan, Wolfgang
据推测，X-连锁的常染色体序列多样性的比例是由不等的性别比例在果蝇种群的影响。我们进行了基因组扫描的单核苷酸多态性（SNP）的378个常染色体基因座在衍生的欧洲人口和一个子集的53个基因座的祖先非洲人口。在这些数据和我们已经获得的X连锁数据的基础上，我们使用了基于合并的最大似然方法来估计两个人群的性别比和人口统计学历史。我们证实了我们以前的研究结果，非洲人口经历了人口规模扩张，而欧洲人口遭受人口规模瓶颈。我们的分析还表明，非洲的女性人口规模大于或等于男性人口规模。相比之下，欧洲人口显示出男性的巨大过剩。然而，这种不平等的性别比例和瓶颈本身并不能解释欧洲人群中X连锁多样性的过度减少（与常染色体上的减少相比）。在欧洲观察到的频率谱和连锁不平衡水平的模式表明，此外，积极的选择必须采取行动，在派生的人口。
It has been hypothesized that the ratio of X-linked to autosomal sequence diversity is influenced by unequal sex ratios in Drosophila melanogaster populations. We conducted a genome scan of single nucleotide polymorphism (SNP) of 378 autosomal loci in a derived European population and of a subset of 53 loci in an ancestral African population. On the basis of these data and our already available X-linked data, we used a coalescent-based maximum-likelihood method to estimate sex ratios and demographic histories simultaneously for both populations. We confirm our previous findings that the African population experienced a population size expansion while the European population suffered a population size bottleneck. Our analysis also indicates that the female population size in Africa is larger than or equal to the male population size. In contrast, the European population shows a huge excess of males. This unequal sex ratio and the bottleneck alone, however, cannot account for the overly strong decrease of X-linked diversity in the European population (compared to the reduction on the autosome). The patterns of the frequency spectrum and the levels of linkage disequilibrium observed in Europe suggest that, in addition, positive selection must have acted in the derived population.