Polarity and temporality of high-resolution Y-chromosome distributions in India identify both indigenous and exogenous expansions and reveal minor genetic influence of central Asian pastoralists
Polarity and temporality of high-resolution Y-chromosome distributions in India identify both indigenous and exogenous expansions and reveal minor genetic influence of central Asian pastoralists
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DOI：
10.1086/499411
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发表时间：
2006-02-01
影响因子：
9.8
通讯作者：
Underhill, PA
中科院分区：
文献类型：
--
作者：
Sengupta, S;Zhivotovsky, LA;Underhill, PA
尽管中亚游牧民族的到来对南亚的社会等级和语言产生了相当大的文化影响，但遗传数据（线粒体和Y染色体）对南亚部落和种姓的遗传起源产生了非常矛盾的推论。我们试图解决这一冲突，使用高分辨率的数据69信息Y染色体二进制标记和10个微卫星标记从一个大的地理，社会和语言代表性的种族群体的南亚。我们发现，中亚对预先存在的基因库的影响是轻微的。大多数印度单倍型群中微卫星变异的累积年龄超过10，000 - 15，000年，这证明了区域分化的古老性。因此，我们的数据不支持的模型，调用一个明显的最近从中亚的遗传输入来解释在南亚观察到的遗传变异。R1 a1和R2单倍型群表明人口复杂性与最近的单一历史不一致。相关的高频R1 a1单倍型组染色体的微卫星分析表明独立的印度河流域和印度半岛地区的最近的历史。我们的数据也更一致的半岛起源的德拉威语比接近印度河的来源和显着的遗传输入与农业相关的地方性扩散。我们的研究结果强调了标记确定的重要性，区分系统发育的终端分支时，归属祖先的组成和时间无论是本土或外源性来源。我们的重新评估表明，前全新世和全新世时代-而不是印欧-扩张塑造了独特的南亚Y染色体景观。
Although considerable cultural impact on social hierarchy and language in South Asia is attributable to the arrival of nomadic Central Asian pastoralists, genetic data ( mitochondrial and Y chromosomal) have yielded dramatically conflicting inferences on the genetic origins of tribes and castes of South Asia. We sought to resolve this conflict, using high-resolution data on 69 informative Y-chromosome binary markers and 10 microsatellite markers from a large set of geographically, socially, and linguistically representative ethnic groups of South Asia. We found that the influence of Central Asia on the pre-existing gene pool was minor. The ages of accumulated microsatellite variation in the majority of Indian haplogroups exceed 10,000 - 15,000 years, which attests to the antiquity of regional differentiation. Therefore, our data do not support models that invoke a pronounced recent genetic input from Central Asia to explain the observed genetic variation in South Asia. R1a1 and R2 haplogroups indicate demographic complexity that is inconsistent with a recent single history. Associated microsatellite analyses of the high-frequency R1a1 haplogroup chromosomes indicate independent recent histories of the Indus Valley and the peninsular Indian region. Our data are also more consistent with a peninsular origin of Dravidian speakers than a source with proximity to the Indus and with significant genetic input resulting from demic diffusion associated with agriculture. Our results underscore the importance of marker ascertainment for distinguishing phylogenetic terminal branches from basal nodes when attributing ancestral composition and temporality to either indigenous or exogenous sources. Our reappraisal indicates that pre-Holocene and Holocene-era-not Indo-European-expansions have shaped the distinctive South Asian Y-chromosome landscape.