The peopling history of continental East Asia revealed by the HLA system

The origin of modern humans in East Asia is a hot issue in molecular anthropology. Based on results from Y chromosome, mtDNA and SNP etc, some scholars proposed that modern humans first entered East Asia by a southern route and expanded northward. However, concerning to the very diverse genetic markers of the HLA system, few analyses have been performed for East Asia. For this reason, we collected and analyzed HLA data from 76 distinct Continental East Asian populations tested for five HLA loci (HLA-A, -B, -C, -DPB1, and/or -DRB1). We observed that some HLA alleles distribute unevenly in the North and in the South, and that the genetic diversity (heterozygosity of the populations) decreased from north to south. While our results support the existence of a southern route, we also conclude that genetic contribution of ancient human migrations through a northern route has probably also been ancient and substantial.东亚地区的现代人起源是分子人类学的热点课题之一。近年来学者通过研究Y染色体、线粒体DNA以及单核苷酸多态性(SNP)等遗传标记物的单倍型在东亚南北地区人群中的分布差异得出最早进入东亚的现代人自南向北扩展的结论。然而在分子人类学领域中扮演重要角色的人类白细胞抗原系统(HLA system)在东亚尚未得到广泛深入的研究。因此我们收集了东亚大陆地区的76个人群的HLA分型数据共涉及五个经典基因座(A、B、C、 DPB1、DRB1)并对这些数据进行了统计学分析。结果表明一些HLA等位基因在东亚南北人群中的分布有明显差异而人群的基因杂合度 (heterozygosity)则自北向南逐渐下降这些结果支持了自南向北迁徙线路的存在同时也揭示出由东亚西北部进入东亚的现代人类也应对东亚人群的遗传结构产生过古老而重要的影响