Department of Biology, Boston College, Chestnut Hill, Massachusetts, USA.
PLoS Genet. 2011 Aug;7(8):e1002236. doi: 10.1371/journal.pgen.1002236. Epub 2011 Aug 18.
As a consequence of the accumulation of insertion events over evolutionary time, mobile elements now comprise nearly half of the human genome. The Alu, L1, and SVA mobile element families are still duplicating, generating variation between individual genomes. Mobile element insertions (MEI) have been identified as causes for genetic diseases, including hemophilia, neurofibromatosis, and various cancers. Here we present a comprehensive map of 7,380 MEI polymorphisms from the 1000 Genomes Project whole-genome sequencing data of 185 samples in three major populations detected with two detection methods. This catalog enables us to systematically study mutation rates, population segregation, genomic distribution, and functional properties of MEI polymorphisms and to compare MEI to SNP variation from the same individuals. Population allele frequencies of MEI and SNPs are described, broadly, by the same neutral ancestral processes despite vastly different mutation mechanisms and rates, except in coding regions where MEI are virtually absent, presumably due to strong negative selection. A direct comparison of MEI and SNP diversity levels suggests a differential mobile element insertion rate among populations.
由于插入事件在进化过程中的积累，移动元件现在几乎占人类基因组的一半。Alu、L1 和 SVA 移动元件家族仍在复制，导致个体基因组之间发生变异。移动元件插入（MEI）已被确定为血友病、神经纤维瘤病和各种癌症等遗传疾病的病因。在这里，我们展示了来自三个主要人群的 185 个样本的 1000 基因组计划全基因组测序数据中 7380 个 MEI 多态性的综合图谱，使用两种检测方法检测到。该目录使我们能够系统地研究 MEI 多态性的突变率、群体分离、基因组分布和功能特性，并将 MEI 与来自同一个体的 SNP 变异进行比较。尽管突变机制和速率大不相同，但 MEI 和 SNPs 的群体等位基因频率都广泛地受到相同的中性祖先过程的描述，除了在编码区域，MEI 几乎不存在，可能是由于强烈的负选择。MEI 和 SNP 多样性水平的直接比较表明，不同人群的移动元件插入率存在差异。
