Schmitt R, Bonatto S L, Freitas L B, Muschner V C, Hill K, Hurtado A M, Salzano F M
Genomic and Molecular Biology Centre, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
Ann Hum Biol. 2004 Jan-Feb;31(1):87-94. doi: 10.1080/03014460310001602063.
The Aché Natives are an especially interesting group of people, due to their distinctive morphological aspect and the fact that only in the last three decades have they established more permanent contact with outside populations. The objectives of the present study were: (a) to verify their distinctiveness in relation to mitochondrial DNA (mtDNA) variability; (b) to ascertain whether the pattern observed was congruent with other genetic studies performed among them; and (c) to establish historical inferences that would explain the eventual similarities or differences.
Sample collection was made at two localities in eastern Paraguay. DNA from 64 maternally unrelated subjects were tested in relation to the mtDNA hypervariable segment 1 (HVS-1) by automatic sequencing.
Fifty-six individuals presented exactly the same haplogroup B founder haplotype; another differed from it by a single transition polymorphism at site 16362, while six other subjects showed an identical haplogroup A founding haplotype. An A/G heteroplasmy at the 16269 site was seen in one haplogroup B individual, probably due to a somatic mutation.
The Aché present distinctive differences and reduced mtDNA HVS-1 variability compared to other South American Natives. Similar differences were observed for other genetic systems. At present it is not clear whether their peculiarities already existed in their founding populations or whether they were secondarily acquired due to a long period of isolation in the humid, subtropical forest.
阿切原住民是一个特别有趣的群体，这是由于他们独特的形态特征，以及直到最近三十年他们才与外部人群建立起更持久联系这一事实。本研究的目的是：（a）验证他们在线粒体DNA（mtDNA）变异性方面的独特性；（b）确定观察到的模式是否与在他们中间进行的其他基因研究一致；（c）建立能够解释最终的相似性或差异的历史推断。
在巴拉圭东部的两个地点进行样本采集。通过自动测序对64名母系无亲缘关系个体的DNA进行线粒体DNA高变区1（HVS-1）检测。
56名个体呈现完全相同的单倍群B奠基者单倍型；另一名个体在16362位点有一个单碱基转换多态性差异；其他6名个体呈现相同的单倍群A奠基者单倍型。在一名单倍群B个体的16269位点发现A/G异质性，可能是由于体细胞突变。
与其他南美原住民相比，阿切人呈现出独特差异且线粒体DNA高变区1变异性降低。在其他遗传系统中也观察到类似差异。目前尚不清楚他们的独特性在其奠基人群中就已存在，还是由于在潮湿的亚热带森林中长期隔离而次生获得的。
