应用STR基因多态性探讨西藏民族群体的遗传关系

Genetic relationships of populations between Tibetan and other ethnic groups lived in Tibet

目的探讨西藏藏族、珞巴族与其他民族的群体遗传学关系。方法利用15个荧光标记的人类常染色体STR位点的引物,对西藏藏族、珞巴族DNA进行了多重PCR扩增,产物在ABI3100遗传分析仪上进行毛细管电泳和基因扫描及分型,并结合文献资料与青海藏族、中国其他4大民族、美国白人及黑人进行比较,计算遗传距离,构建系统发生树,分析了他们之间的遗传关系。结果青海藏族和昌都藏族间遗传距离最近(0.022 3),其次是西藏藏族与昌都藏族间距离(0.031 2);珞巴族与西藏藏族遗传距离最近(0.027 8),其次是昌都、青海藏族(0.062 5和0.077 6),再次为蒙古族(0.073 3)、宁夏回族(0.110 1),珞巴族与维吾尔族的遗传距离最远(0.219 1);藏族三个群体与珞巴族先聚类,其次与蒙古族、西安汉族、宁夏回族和新疆维吾尔族聚类,中华民族8个群体聚为一类。再与白种人及黑种人聚类。结论民族的地理分布和民族历史基本上是一致的,并可为结合历史和考古资料综合分析藏族和珞巴族的起源、迁移、形成和发展提供遗传学依据。

Objective To study the genetic relationships of Tibetan and Luoba ethnic lived in Tibet, China by using STR polymorphism. Methods We collected the blood samples of unrelated individuals from different groups and sequenced the STR data with ABI 3100 genetic analysis apparatus, and then analyzed all the data with the statistical methods. Compared the STR data of Tibetan, Luoba with those of other four Chinese ethnic groups and United White and Black, counted genetic distances, constructed phylogenesis tree, analysed the genetic relationships among eight Chinese ethnic groups and United White and Black. Results The genetic distances between Qinghai Tibetan and Changdu Tibetan is very near (0. 022 3) firstly, the genetic distances between Tibet Tibetan and Changdu Tibetan is 0.031 2. Luoba and Tibet Tibetan are close to each other (0. 027 8), next to Changdu Tibetan (0. 062 5), Qinghai Tibetan (0. 0776), Mongolian(0. 073 3), Ningxia Hui(0. 110 1). The genetic distance between Luoba and Uygr is farthest among eight Chinese populations. Three groups of Tibetan cluster with Luoba firstly, then cluster with Mongolia, Xi'an Han, Ningxia Hui and Uygr. Eight Chinese populations cluster together with United White and Black. Conclusion The results of this study are consistent with geography distributing, histories of these ethnic groups basically. That can provide the genetic proofs for investiation origin, magaration, form and development.