Breguet G, Bütler R, Bütler-Brunner E, Sanchez-Mazas A
Department of Anthropology, University of Geneva, Switzerland.
Am J Hum Genet. 1990 Mar;46(3):502-17.
The aim of this investigation is to examine the distribution of the Ag immunological polymorphism in human populations on a worldwide scale and to look for possible explanations of this distribution in the field of modern human peopling history and Ag-system evolution. Extensive Ag-antigene typings were carried out on 13 human population samples, including sub-Saharan African, European, west and east Asiatic, Melanesian, Australian aborigine, and Amerindian groups. Complete Ag-haplotype frequencies were estimated by maximum-likelihood-score procedures, and the data were analyzed by genetic distance computations and principal coordinate projections. With the exception of the Amerindian sample, the Ag polymorphism is shown to be highly polymorphic in all the populations tested. Their genetic relationships appear to be closely correlated to their geographical distribution. This suggests that the Ag system has evolved as a neutral or nearly neutral polymorphism and that it is highly informative for modern human peopling history studies. From the worldwide Ag haplotypic distributions, a model for the Ag molecular structure is derived. According to this model and to the most recent results obtained from molecular data, the establishment of the Ag polymorphism could be explained by several mutations and recombination events between the haplotypes most frequently found in human populations today. As a conclusion, genetic and paleontological data suggest that the genetic structure of caucasoid populations (located from North Africa to India) may be the least differentiated from an ancestral genetic stock. Worldwide genetic differentiations are properly explained as the results of westward and eastward human migrations from a Near East-centered but undefined geographical area where modern humans may have originated. The importance of Ag polymorphism analyses for the reconstruction of human settlement history and origins is discussed in the light of the main conclusions of the most recent genetic polymorphism studies.
本研究的目的是在全球范围内研究人类群体中Ag免疫多态性的分布，并在现代人类迁徙历史和Ag系统进化领域寻找这种分布的可能解释。对13个人类群体样本进行了广泛的Ag - 抗原分型，包括撒哈拉以南非洲人、欧洲人、西亚和东亚人、美拉尼西亚人、澳大利亚原住民和美洲印第安人群体。通过最大似然评分程序估计完整的Ag单倍型频率，并通过遗传距离计算和主坐标投影对数据进行分析。除美洲印第安人样本外，Ag多态性在所有测试群体中均表现出高度多态性。它们的遗传关系似乎与其地理分布密切相关。这表明Ag系统已作为一种中性或近中性多态性进化，并且对于现代人类迁徙历史研究具有很高的信息量。从全球Ag单倍型分布中，推导了一个Ag分子结构模型。根据这个模型和从分子数据获得的最新结果，Ag多态性的建立可以用当今人类群体中最常见的单倍型之间的几个突变和重组事件来解释。总之，遗传和古生物学数据表明，高加索人群体（从北非到印度）的遗传结构可能与祖先遗传种群的差异最小。全球遗传分化可以恰当地解释为人类从以近东为中心但未定义的地理区域向西和向东迁移的结果，现代人类可能起源于此。根据最近遗传多态性研究的主要结论，讨论了Ag多态性分析对重建人类定居历史和起源的重要性。
