Silva Dayse A, Carvalho Elizeu, Costa Guilherme, Tavares Lígia, Amorim António, Gusmão Leonor
Laboratório de Diagnósticos por DNA, Departamento de Ensino de Ciências e Biologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, 524 Rio de Janeiro, Brazil.
Am J Hum Biol. 2006 Nov-Dec;18(6):829-37. doi: 10.1002/ajhb.20567.
The present-day Brazilian gene pool is known to be the outcome of an admixture process of populations from different origins, mainly Amerindians, Europeans, and Africans. It is also known that in Brazil, a wide variation in the admixture process occurred in different regions of the country or even in different subpopulations from the same region. In the present study, we aimed to characterize the male lineages present in the Rio de Janeiro population, the second most populated of the 26 Brazilian states. A random sample of 127 unrelated males from Rio de Janeiro was typed for 28 Y-chromosome-specific biallelic markers. In total, 17 different haplogroups were defined within our sample, most of them of European ancestry (88.1%). Those of sub-Saharan African origin (E3a) amounted to 7.9%, while only 2 males carried Amerindian lineages (characterized by the presence of an M3 mutation: haplogroup Q3). Using both Y-STR haplotype and Y-SNP haplogroup information, genetic distances were calculated between the subgroup of Rio de Janeiro males carrying European haplogroups and the Portuguese population. Low, nonsignificant, values were obtained. Thus, in contrast with what is observed in their female counterparts, the vast majority of the present Rio de Janeiro male gene pool is of European extraction, while the original Amerindian lineages are residual and much less frequent than the sub-Saharan component resulting from the slave trade. These observations can be interpreted as the signature of the strong gender asymmetry of the admixture processes in colonial systems.
当今巴西的基因库是来自不同起源人群混合过程的结果，主要是美洲印第安人、欧洲人和非洲人。人们还知道，在巴西，混合过程在该国不同地区甚至同一地区的不同亚群体中存在很大差异。在本研究中，我们旨在描述里约热内卢人口中的男性谱系特征，里约热内卢是巴西26个州中人口第二多的城市。对来自里约热内卢的127名无关男性的随机样本进行了28个Y染色体特异性双等位基因标记的分型。在我们的样本中总共定义了17种不同的单倍群，其中大多数具有欧洲血统（88.1%）。撒哈拉以南非洲起源的单倍群（E3a）占7.9%，而只有2名男性携带美洲印第安人谱系（以存在M3突变特征：单倍群Q3）。利用Y-STR单倍型和Y-SNP单倍群信息，计算了携带欧洲单倍群的里约热内卢男性亚组与葡萄牙人群之间的遗传距离。得到的值较低且无统计学意义。因此，与女性情况不同的是，目前里约热内卢男性基因库的绝大多数来自欧洲血统，而原始的美洲印第安人谱系残留较少，且比奴隶贸易带来的撒哈拉以南成分的频率要低得多。这些观察结果可以解释为殖民体系中混合过程强烈性别不对称的特征。
