Natural Selection and the Distribution of Identity-by-Descent in the Human Genome
Natural Selection and the Distribution of Identity-by-Descent in the Human Genome
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DOI：
10.1534/genetics.110.113977
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发表时间：
2010-09-01
期刊：
影响因子：
3.3
通讯作者：
Nielsen, Rasmus
中科院分区：
文献类型：
--
作者：
Albrechtsen, Anders;Moltke, Ida;Nielsen, Rasmus
最近，人们对检测人类基因组中的自然选择产生了相当大的兴趣。选择通常倾向于增加种群中个体的血统认同（IBD），许多检测最近和正在进行的阳性选择的方法间接利用了这一点。在这篇文章中，我们展示了过度的IBD共享是自然选择的一般特性，我们展示了这一事实使得检测几种类型的选择成为可能，包括一种难以检测的类型：作用于常设遗传变异的选择。受此启发，我们使用最近开发的一种方法，从全基因组数据中识别个体之间的IBD共享，扫描来自新的HapMap第三阶段项目的人群，寻找IBD共享过多的区域，以确定人类基因组中处于强烈的、最近的选择下的区域。HLA区域是迄今为止显示出最极端信号的区域，这表明最近作用于人类基因组的许多强选择都与免疫相关，并作用于HLA位点。由于均衡优势并不倾向于增加IBD，我们认为这种类型的选择不能解释我们的观察结果。
There has recently been considerable interest in detecting natural selection in the human genome. Selection will usually tend to increase identity-by-descent (IBD) among individuals in a population, and many methods for detecting recent and ongoing positive selection indirectly take advantage of this. In this article we show that excess IBD sharing is a general property of natural selection and we show that this fact makes it possible to detect several types of selection including a type that is otherwise difficult to detect: selection acting on standing genetic variation. Motivated by this, we use a recently developed method for identifying IBD sharing among individuals from genome-wide data to scan populations from the new HapMap phase 3 project for regions with excess IBD sharing in order to identify regions in the human genome that have been under strong, very recent selection. The HLA region is by far the region showing the most extreme signal, suggesting that much of the strong recent selection acting on the human genome has been immune related and acting on HLA loci. As equilibrium overdominance does not tend to increase IBD, we argue that this type of selection cannot explain our observations.