Abstract

The Roma Diaspora—traditionally known as Gypsies—remains among the least explored population migratory events in historical times. It involved the migration of Roma ancestors out-of-India through the plateaus of Western Asia ultimately reaching Europe. The demographic effects of the Diaspora—bottlenecks, endogamy, and gene flow—might have left marked molecular traces in the Roma genomes. Here, we analyze the whole-genome sequence of 46 Roma individuals pertaining to four migrant groups in six European countries. Our analyses revealed a strong, early founder effect followed by a drastic reduction of ∼44% in effective population size. The Roma common ancestors split from the Punjabi population, from Northwest India, some generations before the Diaspora started, <2,000 years ago. The initial bottleneck and subsequent endogamy are revealed by the occurrence of extensive runs of homozygosity and identity-by-descent segments in all Roma populations. Furthermore, we provide evidence of gene flow from Armenian and Anatolian groups in present-day Roma, although the primary contribution to Roma gene pool comes from non-Roma Europeans, which accounts for >50% of their genomes. The linguistic and historical differentiation of Roma in migrant groups is confirmed by the differential proportion, but not a differential source, of European admixture in the Roma groups, which shows a westward cline. In the present study, we found that despite the strong admixture Roma had in their diaspora, the signature of the initial bottleneck and the subsequent endogamy is still present in Roma genomes.

中文翻译：

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最近的共同起源，减少的种群规模和明显的混合已经塑造了欧洲罗姆人的基因组。

摘要

罗姆人散居地（传统上被称为吉普赛人）仍然是历史上最少被调查的人口迁徙事件之一。它涉及罗姆人的祖先从印度境外迁移到西亚高原，最终到达欧洲。散居人口的人口统计学影响（瓶颈，内婚和基因流动）可能在罗姆人基因组中留下了明显的分子痕迹。在这里，我们分析了六个欧洲国家中属于四个移民群体的46个罗姆人的全基因组序列。我们的分析揭示了强大的早期创建者效应，随后有效人口规模急剧减少了约44％。罗姆人的共同祖先是从印度西北部的旁遮普邦人口中分离出来的，大约在距今2000年前的流散者开始之前的几代人。在所有罗姆人群体中，出现大量纯合性和后裔身份认同段表明了最初的瓶颈和随后的内婚现象。此外，我们提供了当今罗姆人亚美尼亚人和安纳托利亚人群体的基因流的证据，尽管对罗姆人基因库的主要贡献来自非罗姆人欧洲人，占他们基因组的50％以上。罗姆人在移民群体中的语言和历史差异是由罗姆人群体中欧洲掺混物的差异比例而不是差异来源所证实的，这表明西线是朝西的。在本研究中，我们发现尽管罗姆人在侨民中有很强的混合物，但罗姆人基因组中仍然存在最初的瓶颈和随后的内婚现象。