The history of African gene flow into Southern Europeans, Levantines, and Jews.
The history of African gene flow into Southern Europeans, Levantines, and Jews.
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DOI：
10.1371/journal.pgen.1001373
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发表时间：
2011-04
期刊：
影响因子：
4.5
通讯作者：
Reich D
中科院分区：
文献类型：
--
作者：
Moorjani P;Patterson N;Hirschhorn JN;Keinan A;Hao L;Atzmon G;Burns E;Ostrer H;Price AL;Reich D
先前的遗传学研究表明，撒哈拉以南非洲的基因在至少45，000年前首次从非洲扩散出去后流入一些西欧亚人群。然而，混合物的比例或其日期一直没有准确的特征。我们分析了来自大约40个西欧亚群体的全基因组多态性数据，结果表明几乎所有南欧人都继承了1%-3%的非洲血统，平均混合日期约为55代前，与罗马帝国末期和随后的阿拉伯移民的北非基因流一致。黎凡特人有4%-15%的非洲血统，平均混合日期约为32代前，与中世纪晚期与埃及的密切政治，经济和文化联系一致。在我们分析的所有八个不同的犹太人群体中，我们还检测到3%-5%的撒哈拉以南非洲血统。对于犹太混血儿，我们得到的平均估计日期约为72代。这可能反映了这些群体的血统来自一个共同的祖先人口，在犹太人散居之前已经有一些非洲血统。据了解，南欧和中东人口从最近的撒哈拉以南非洲移民中继承了一小部分遗传物质，但没有估计这种基因流动的确切比例或其日期。在这里，我们应用基因组方法表明，非洲血统在许多南欧群体中的比例为1%-3%，在中东群体中为4%-15%，在犹太群体中为3%-5%。为了估计混合发生的日期，我们开发了一种新的方法，估计混合血统个体中不同血统的染色体片段的大小。我们使用计算机模拟验证，该方法产生有用的估计人口混合日期在过去的300代。通过将该方法应用于西欧亚人，我们表明，在南欧的日期是一致的罗马帝国和随后的阿拉伯移民期间的事件。犹太群体的日期更老，与古典或圣经时代的事件一致，这些事件可能发生在犹太人口的共同历史中。
Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas. Southern Europeans and Middle Eastern populations are known to have inherited a small percentage of their genetic material from recent sub-Saharan African migrations, but there has been no estimate of the exact proportion of this gene flow, or of its date. Here, we apply genomic methods to show that the proportion of African ancestry in many Southern European groups is 1%–3%, in Middle Eastern groups is 4%–15%, and in Jewish groups is 3%–5%. To estimate the dates when the mixture occurred, we develop a novel method that estimates the size of chromosomal segments of distinct ancestry in individuals of mixed ancestry. We verify using computer simulations that the method produces useful estimates of population mixture dates up to 300 generations in the past. By applying the method to West Eurasians, we show that the dates in Southern Europeans are consistent with events during the Roman Empire and subsequent Arab migrations. The dates in the Jewish groups are older, consistent with events in classical or biblical times that may have occurred in the shared history of Jewish populations.