Comparative study on genetic differences between Mongolian and Japanese populations

于2005年8月在乌兰巴托（中部地区）、乌兰巴托（西部地区）和达兰扎德加德（南部戈壁沙漠地区），以及于2006年6月在温杜卡安（东北部地区）、乔巴山（东部地区），从每200名知情同意的健康蒙古人中采集口腔拭子DNA样本。从五个地区人群的总共1,000个口腔拭子中提取DNA并进行定量。使用AmpFlSTR Identifiler试剂盒对所有这些样本进行15个STR基因座和用于性别确定的釉原蛋白的基因分型。在这些样本中，97份来自乌兰巴托，95份来自乌兰巴托，100份来自Dalandzadgad，117份来自Choybalsan，84份来自Undurkhaan男性样本也使用AmpFlSTR Yfiler试剂盒进行了分析。计算15个常染色体STR标记的等位基因频率数据，并对每个区域人群中的每个位点进行三次Hardy-Weinberg平衡（HWE）检验。在所有这五个群体的所有位点上，所有三个测试都没有观察到HWE偏离。利用已发表的和我们的数据，这15个STR基因座在日本区域人群和区域人群在东亚和东南亚，以及5个区域蒙古族人群在这项研究中，邻居连接（NJ）树的基础上DA遗传距离的构建和多维尺度（MDS）分析。结果表明，5个蒙古族地区种群在NJ树中均聚为一类，其分布与MDS图中的地理分布相一致。通过对17个Y-STR的单倍型分析，发现日本人有两个独特的聚类，表明蒙古族5个地区群体与日本地区群体之间的遗传差异并不小于蒙古族群体与其地理上邻近的群体之间的遗传差异，日本人起源于蒙古布里亚特人的假说可能是不一致的。

DNA samples as buccal swabs collected from each 200 healthy Mongolian individuals with informed consents in Ulaanbaatar (central area), Ulaangom (western area) and Dalandzadgad (in the Gobi desert as southern area) on August, 2005, and in Undurkhaan (northeastern area), Choybalsan (eastern area) on June, 2006. DNA from total 1,000 buccal swabs in five regional populations were extracted and quantified. All of those samples were genotyped for 15 STR loci and amelogenin for gender determination using an AmpFlSTR Identifiler kit. In those samples, 97 from Ulaanbaatar, 95 from Ulaangom, 100 from Dalandzadgad, 117 from Choybalsan, and 84 from Undurkhaan male samples were also analyzed using an AmpFlSTR Yfiler kit. Allele frequency data were calculated for 15 autosomal STR markers, and three tests for Hardy-Weinberg equilibrium (HWE) were performed for each locus in each regional population. No departure from HWE at all the loci in all of those five populations was observed by all the three tests. Using published and our data for those 15 STR loci in Japanese regional populations and regional populations in East and Southeast Asia, and five regional Mongolian populations in this study, a Neighbor-Joining (NJ) tree based on DA genetic distance was constructed and a Multi-Dimensional Scaling (MDS) analysis was performed. As a result, all of the five regional Mongolian populations formed a cluster in the NJ tree, and those distributions were consistent with those geographical distributions in the MDS plot. By the haplotype analysis for 17 Y-STRs, two unique clusters for Japanese were observed.In the present study, it is suggested that genetic differences between five regional Mongolian populations and Japanese regional populations are not smaller than those between those Mongolian populations and their geographically closer populations, and that a hypothesis where the origin of Japanese exists among Buryat in Mongolia is potentially inconsistent.