利用HapMap数据发现人类基因组中正选择的“候选区域”

A Genome Scanning for Regions Under Selective Sweep Based on HapMap Data

人类基因组国际单体型图计划(The International Haplotype Map Project,HapMap)旨在构建全基因组范围的常见遗传变异数据库,为复杂性疾病、人类进化和其它遗传学研究提供基础数据。此研究基于HapMap计划第Ⅰ期数据,通过群体基因组学策略对亚、欧、非人群中的正选择信号进行扫描。在基因组范围建立了一个包含多层次信息(基因、窗口、大型区域)的正选择图谱。研究表明:人类基因组中存在一定程度的正选择,正选择的"候选窗口"占总筛查窗口的～5%;基因组中的正选择信号集中于某些特定的染色体区域;确定了62个可能受到强正选择的大型区域,以及区域内相应的88个受到强正选择的"候选基因"。研究还发现人群特异的选择在人群的分化过程中发挥了重要的作用。此研究将为后续的人类进化和自然选择研究提供新的线索。

The aim of the International HapMap Project is to understand the patterns of common genetic diversity in the human genome,and to accelerate studies of the human evolution and complex disease. We report here a genome-wide scan for signatures of positive selection based on single nucleotide polymorphism （SNP） data from HapMap. In all three HapMap samples （ASN,CEU,and YRI）,we find widespread signals of positive selection,and a clear clustering of candidate windows into distinct region. This survey also identified 62 Contiguous Regions of Heterozygosity Reduction （CRHRs）,which putatively subject to strong selective sweeps.Furthermore,most signals of positive selection are population-specific,though a significant excess are shared across samples.Our results suggest that positive selection may contribute to genetic differentiation among human populations.And our analysis provides new clues for our understanding the positive selection in human history.