Native American genetic variation remains underrepresented in most catalogs of human genome sequencing data. Previous genotyping efforts have revealed that Mexico's indigenous population is highly differentiated and substructured, thus potentially harboring higher proportions of private genetic variants of functional and biomedical relevance. Here we have targeted the coding fraction of the genome and characterized its full site frequency spectrum by sequencing 76 exomes from five indigenous populations across Mexico. Using diffusion approximations, we modeled the demographic history of indigenous populations from Mexico with northern and southern ethnic groups splitting 7.2 kya and subsequently diverging locally 6.5 kya and 5.7 kya, respectively. Selection scans for positive selection revealed BCL2L13 and KBTBD8 genes as potential candidates for adaptive evolution in Rarámuris and Triquis, respectively. BCL2L13 is highly expressed in skeletal muscle and could be related to physical endurance, a well-known phenotype of the northern Mexico Rarámuri. The KBTBD8 gene has been associated with idiopathic short stature and we found it to be highly differentiated in Triqui, a southern indigenous group from Oaxaca whose height is extremely low compared to other Native populations.

中文翻译：

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从76个人类外显子组推断出墨西哥土著人的人口历史和基因差异。

在大多数人类基因组测序数据目录中，美洲原住民的遗传变异仍未得到充分体现。先前的基因分型研究表明，墨西哥的土著人口高度分化和亚结构化，因此潜在地藏有更高比例的具有功能和生物医学意义的私人遗传变异。在这里，我们靶向基因组的编码部分，并通过对来自墨西哥五个土著居民的76个外显子组进行测序来表征其完整位点频谱。使用扩散近似，我们对墨西哥土著居民的人口历史进行了建模，北部和南部种族分裂了7.2 kya，随后分别在当地分裂了6.5 kya和5.7 kya。选择扫描的阳性选择揭示了BCL2L13和KBTBD8基因分别是Rarámuris和Triquis适应性进化的潜在候选者。BCL2L13在骨骼肌中高表达，可能与身体耐力有关，这是北墨西哥Rarámuri的一个著名表型。KBTBD8基因与特发性矮小身材有关，我们发现它在Triqui中高度分化，Triqui是来自瓦哈卡州的南部土著群体，与其他土著居民相比其高度极低。