Laboratory of Anthropology, Genetics and Peopling History (AGP lab), Anthropology Unit, Department of Genetics and Evolution, University of Geneva, 12 rue Gustave-Revilliod, CH-1211, Geneva, Switzerland,
Immunogenetics. 2014 Mar;66(3):153-60. doi: 10.1007/s00251-014-0757-6. Epub 2014 Jan 22.
Genetic differences between Northeast Asian (NEA) and Southeast Asian (SEA) populations have been observed in numerous studies. At the among-population level, despite a clear north-south differentiation observed for many genetic markers, debates were led between abrupt differences and a continuous pattern. At the within-population level, whether NEA or SEA populations have higher genetic diversity is also highly controversial. In this study, we analyzed a large set of HLA data from East Asia in order to map the genetic variation among and within populations in this continent and to clarify the distribution pattern of HLA lineages and alleles. We observed a genetic differentiation between NEA and SEA populations following a continuous pattern from north to south, and we show a significant and continuous decrease of HLA diversity by the same direction. This continuity is shaped by clinal distributions of many HLA lineages and alleles with increasing or decreasing frequencies along the latitude. These results bring new evidence in favor of the "overlapping model" proposed previously for East Asian peopling history, whereby modern humans migrated eastward from western Eurasia via two independent routes along each side of the Himalayas and, later, overlapped in East Asia across open land areas. Our study strongly suggests that intensive gene flow between NEA and SEA populations occurred and shaped the latitude-related continuous pattern of genetic variation and the peculiar HLA lineage and allele distributions observed in this continent. Probably for a very long period, the exact duration of these events remains to be estimated.
在许多研究中观察到东北亚（NEA）和东南亚（SEA）人群之间存在遗传差异。在种群间水平上，尽管许多遗传标记观察到明显的南北分化，但在突然差异和连续模式之间存在争议。在种群内水平上，NEA 或 SEA 人群是否具有更高的遗传多样性也存在很大争议。在这项研究中，我们分析了东亚的大量 HLA 数据，以便绘制该大陆内和人群间的遗传变异图谱，并阐明 HLA 谱系和等位基因的分布模式。我们观察到 NEA 和 SEA 人群之间存在连续的遗传分化，从北到南，我们还表明 HLA 多样性以相同的方向显著且连续地减少。这种连续性由许多 HLA 谱系和等位基因的渐变分布形成，其频率沿着纬度增加或减少。这些结果为之前提出的东亚人群历史的“重叠模型”提供了新的证据，即现代人从欧亚大陆西部通过喜马拉雅山两侧的两条独立路线向东迁移，后来在东亚开阔的土地上重叠。我们的研究强烈表明，NEA 和 SEA 人群之间发生了强烈的基因流动，形成了与纬度相关的遗传变异连续模式，以及在该大陆观察到的特殊 HLA 谱系和等位基因分布。可能在很长一段时间内，这些事件的确切持续时间仍有待估计。
