Comparative study on genetic differences between Mongolian and Japanese populations

2005年8月，在乌兰巴托（中部地区）、乌兰戈姆（西部地区）和达兰扎加德（南部戈壁沙漠地区），以及2006年6月在undurkhan（东北部地区）、乔巴山（东部地区），经知情同意，从每200名健康蒙古人的口腔拭子中采集DNA样本。从5个地区人群共1000份口腔拭子中提取DNA并进行量化。所有样本均使用AmpFlSTR鉴别试剂盒进行15个STR位点的基因分型，并使用ampelgengenin进行性别鉴定。在这些样本中，97个来自乌兰巴托，95个来自乌兰戈姆，100个来自达兰扎加德，117个来自乔巴桑，84个来自undurkhan的男性样本也使用AmpFlSTR过滤试剂盒进行了分析。计算了15个常染色体STR标记的等位基因频率数据，并对每个区域人群的每个位点进行了3次Hardy-Weinberg平衡（HWE）检测。所有三种检测均未观察到这五个人群中所有位点偏离HWE。利用已发表和本研究的日本、东亚和东南亚地区人群以及蒙古5个地区人群的15个STR基因座数据，构建了基于DA遗传距离的邻居连接（NJ）树，并进行了多维尺度（MDS）分析。结果表明，5个区域蒙古人种群在NJ树中均形成一个聚类，其分布与MDS图中的地理分布一致。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。在本研究中，我们认为蒙古人和日本人的遗传差异并不比蒙古人和他们地理上更接近的人群之间的遗传差异小，并且认为日本人起源于蒙古布里亚特人的假设可能是不一致的。

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.