DNA tests probe the genomic ancestry of Brazilians
DNA tests probe the genomic ancestry of Brazilians
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DOI：
10.1590/s0100-879x2009005000026
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发表时间：
2009-10-01
影响因子：
2.3
通讯作者：
Bydlowski, S.P.
中科院分区：
文献类型：
--
作者：
Pena, S.D.J.;Bastos-Rodrigues, L.;Bydlowski, S.P.
我们回顾了我们实验室的研究，使用不同的分子工具来描述巴西人的血统，参考他们的美洲印第安人、欧洲人和非洲人的血统。最初，我们使用单亲 DNA 标记来研究不同的 Y 染色体和线粒体 DNA 谱系对当今人群的贡献。欧洲雄性与美洲印第安人和非洲雌性之间的高水平遗传混合和强定向交配被揭开。接下来我们分析了不同类型的双亲常染色体多态性。特别有用的是一组 40 个插入删除多态性 (indels)，在全世界范围内进行研究后证明，它们在区分美洲印第安人、欧洲人和撒哈拉以南非洲人方面非常敏感。当这些标记应用于巴西人的研究时，证实了广泛的基因组混合，但也展示了 19 世纪和 20 世纪大规模欧洲移民浪潮的强烈印记。观察到的个体祖先的高度变异性表明，每个巴西人的镶嵌基因组中都具有单一比例的美洲印第安人、欧洲人和非洲祖先。在巴西，人们无法根据基因组祖先来预测人的肤色，也无法预测相反的情况。巴西人应该以个人为基础进行评估，将其视为 1.9 亿人，而不是有色人种群体的成员。
We review studies from our laboratories using different molecular tools to characterize the ancestry of Brazilians in reference to their Amerindian, European and African roots. Initially we used uniparental DNA markers to investigate the contribution of distinct Y chromosome and mitochondrial DNA lineages to present-day populations. High levels of genetic admixture and strong directional mating between European males and Amerindian and African females were unraveled. We next analyzed different types of biparental autosomal polymorphisms. Especially useful was a set of 40 insertion-deletion polymorphisms (indels) that when studied worldwide proved exquisitely sensitive in discriminating between Amerindians, Europeans and Sub-Saharan Africans. When applied to the study of Brazilians these markers confirmed extensive genomic admixture, but also demonstrated a strong imprint of the massive European immigration wave in the 19th and 20th centuries. The high individual ancestral variability observed suggests that each Brazilian has a singular proportion of Amerindian, European and African ancestries in his mosaic genome. In Brazil, one cannot predict the color of persons from their genomic ancestry nor the opposite. Brazilians should be assessed on a personal basis, as 190 million human beings, and not as members of color groups.