Y chromosome diversity in Brazilians: switching perspectives from slow to fast evolving markers
Y chromosome diversity in Brazilians: switching perspectives from slow to fast evolving markers
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DOI：
10.1007/s10709-005-1454-z
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发表时间：
2006-01-01
期刊：
影响因子：
1.5
通讯作者：
Santos, FR
中科院分区：
文献类型：
--
作者：
Carvalho-Silva, DR;Tarazona-Santos, E;Santos, FR
我们以前已经表明，“白色”巴西人的Y染色体有其直接的地理起源在欧洲，低频率的撒哈拉以南非洲染色体和美洲印第安人的贡献几乎没有。Y染色体上缓慢进化的多态性的分型也显示巴西人和葡萄牙人之间没有差异，大部分欧洲移民到巴西，甚至来自巴西不同地区的巴西人之间也没有差异，后者与mtDNA数据形成鲜明对比。为了测试缺乏分化是否是性别偏见而不是标记偏见的现象，我们决定研究来自巴西和葡萄牙的样本中更快进化的Y染色体标记。这项工作揭示的人口结构证实，巴西和葡萄牙之间确实没有显着差异，巴西四个地理区域内没有人口分化，这表明这种现象与标记类型的性质无关。然而，快速发展的标记确实发现了巴西比葡萄牙更高的种群多样性，这可以解释为几个移民波携带的不同欧洲Y染色体输入巴西。我们目前的数据突出了分型和结合Y标记的意义，这些标记根据不同的突变速度发展，以有效地评估给定人群的多样性水平，并可应用于来自不同地理来源的人群的研究，如巴西人。
We have previously shown that the Y chromosomes of 'white' Brazilians have their immediate geographical origin in Europe, with low frequency of sub-Saharan African chromosomes and virtual absence of Amerindian contribution. The typing of slow evolving polymorphisms on the Y chromosome also revealed no differences between Brazilians and Portuguese, the bulk of European immigrants to Brazil, and even among Brazilians from distinct regions of Brazil, the latter being in sharp contrast with mtDNA data. In order to test if the lack of differentiation is a sex-biased and not a marker-biased phenomenon, we decided to study faster evolving Y chromosome markers in samples from Brazil and Portugal previously studied. The population structure revealed by this work confirmed that there were indeed no significant differences between Brazil and Portugal and no population differentiation within the four geographical regions of Brazil, suggesting that this phenomenon is unrelated to the nature of the markers typed. Nevertheless the fast evolving markers did uncover a higher within population diversity in Brazil than Portugal, which could be explained by the input of diverse European Y chromosomes carried by several migration waves to Brazil. Our present data highlight the significance of typing and combining Y markers that evolve according to distinct mutational paces to usefully assess the levels of diversity in a given population, and can be applied in the study of populations derived from distinct geographical origins such as the Brazilians.