Genetic polymorphism and population structure of Torghut Mongols and comparison with a Mongolian population 3000 kilometers away
Genetic polymorphism and population structure of Torghut Mongols and comparison with a Mongolian population 3000 kilometers away
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土尔扈特蒙古族遗传多态性、群体结构及其与3000公里外蒙古族群体的比较
DOI：
10.1016/j.fsigen.2019.07.017
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发表时间：
2019
影响因子：
3.1
通讯作者：
Sun Hongyu
中科院分区：
文献类型：
--
作者：
Wu Riga;Li Ran;Wang Nana;Peng Dan;Li Haixia;Zhang Yinming;Zheng Chenghao;Sun Hongyu
蒙古人在世纪蒙古帝国的迅速扩张中，在塑造现代欧亚大陆的文化和遗传结构方面发挥了关键作用。虽然蒙古帝国的历史方面有很好的记录，但对蒙古人口遗传变异的研究仍然不足。在这项研究中，我们检测了居住在中国伊犁地区的70名托尔呼特蒙古人的遗传多样性，并与居住在3000公里外的88名扎鲁特蒙古人进行了比较。本研究对200多个法医学相关的遗传标记进行了基因分型，包括常染色体短串联重复序列（A-STR）、X染色体STR（X-STR）、Y染色体STR（Y-STR）、身份信息单核苷酸多态性（iiSNPs）、祖先信息单核苷酸多态性（aiSNPs）和表型信息单核苷酸多态性（piSNPs）。STR分型结果显示，在吐尔尕特蒙古族中发现的80个等位基因（A-STR 39个，Y-STR 25个，X-STR 16个，占554个等位基因的14.4%）在扎赉特蒙古族中未发现;在扎赉特蒙古族中发现的155个等位基因（A-STR 84个，Y-STR 59个，X-STR 12个，占630个等位基因的24.6%）在吐尔尕特蒙古族中未发现。法医学参数的计算表明，这里分析的STR和SNPs可以用于法医学应用。通过主成分分析（PCA）、系统发育树和STRUCTURE分析等方法对两个蒙古族群体进行比较，结果表明两个蒙古族群体的遗传背景相近，但也存在遗传差异。当基于序列的A-STR和iiSNPs均被纳入STRUCTURE分析时，土尔扈特人群与维吾尔族人群的相似性高于与扎赉特蒙古族人群的相似性，表明两个蒙古族人群之间存在一定的群体结构差异。Y-DNA单倍群预测结果表明，尽管单倍群C（C2-M217）在两个蒙古族群体中均占优势，但单倍群O2-M122在土尔扈特蒙古族群体中很少出现，这使土尔扈特蒙古族与其他蒙古族群体有了明显的区别。这项研究不仅揭示了两个蒙古部落的遗传特征，为法医学应用提供了有价值的频率数据，而且两个蒙古人群的遗传模式也提供了一个遗传证据，证明土尔扈特蒙古人可能是通过历史记录中的蒙古族和突厥族游牧群体的逐渐混合而发展起来的。这项研究还强调，必须建立考虑到族裔和地理位置信息的区域参考数据库，而不是建立一个更通用的参考数据库，以供法医应用。
Mongolians played a pivotal role in shaping the culture and genetic architecture of modern Eurasia through the rapid expansion of the Mongol Empire in the 13th century. While the historical aspects of the Mongolian Empire are well documented, research on the genetic variations among Mongolian populations is still insufficient. In this study, we examined the genetic diversity of 70 Torghut Mongols residing in the Ili region of China compared with 88 Jalaid Mongols residing 3000 km away. Over 200 forensically relevant genetic markers, including autosomal short tandem repeats (A-STRs), X chromosomal STRs (X-STRs), Y chromosomal STRs (Y-STRs), identity-informative single nucleotide polymorphisms (iiSNPs), ancestry-informative SNPs (aiSNPs), and phenotype-informative SNPs (piSNPs), were genotyped to uncover the genetic polymorphism of the Torghut Mongols. The STR genotyping results showed that 80 alleles (39 A-STRs, 25 Y-STRs, and 16 X-STRs; 14.4% of 554 alleles) identified in Torghut Mongols were not identified in Jalaid Mongols, while 155 alleles (84 A-STRs, 59 Y-STRs and 12 X-STRs; 24.6% of 630 alleles) identified in Jalaid Mongols were not observed in Torghut Mongols. Calculation of the forensic parameters demonstrated that the STRs and SNPs analyzed here could be employed in forensic applications. Interpopulation comparisons via principal component analysis (PCA), phylogenetic tree, and STRUCTURE analysis showed that the two Mongolian populations were closely related by their genetic background, although genetic differences were also discovered. When both the sequence-based A-STRs and iiSNPs were included in the STRUCTURE analysis, the Torghut population was more similar to the Uyghur population than to Jalaid Mongols, indicating certain population structure differences between the two Mongolian populations. The Y-DNA haplogroup prediction showed that although haplogroup C (C2-M217) was dominant in both Mongolian populations, haplogroup O2-M122 was rarely presented in Torghut Mongols, which differentiated the Torghut Mongols from the other Mongolian populations. This study not only uncovered the genetic features of the two Mongolian tribes, providing valuable frequency data for forensic applications, but the genetic patterns of the two Mongolian populations also provide a genetic evidence that the Torghut Mongols may have developed via the gradual intermixing of nomadic groups of Mongol and Turkic origin, as recorded in historical records. This study also highlighted the importance of building regional reference databases that consider both ethnic and geographic location information, instead of a more universal reference database, for forensic applications.