内蒙古地区四个民族九个X短串联重复序列位点的多态性研究

Genetic variation of 9 X-linked short tandem repeat loci among four populations of Inner Mongolian

目的研究内蒙古地区蒙古族、鄂温克族、鄂伦春族、达斡尔族民族x染色体遗传结构及其变化规律，了解9个位点的法医学、群体遗传学应用价值及4个民族间的亲属关系。方法以9个X短串联重复序列（short tandem repeats, X-STR） 位点（DXS6789, DXS101, DXS8378, DXS7132, DXS7133, DXS7423,DXS6804, DXS6799 和HPRTB）作为遗传标记，通过等位基因频率、杂合度、多态信息量等遗传学指标，以及不同群体之间的差异性比较、遗传距离分析和聚类分析，调查内蒙古地区4个主要少数民族群体遗传结构及其变化规律。结果这9个位点在民族间分布具有不同特点，多数具有中等程度多态性，可作为法医学和人类遗传学分析标记。遗传距离和聚类分析显示蒙古族与西安汉族、鄂伦春族与达斡尔族之间具有较近的遗传关系，该结果接近实际语系关系、文化特点及历史记载。结论研究表明，这9个X—SIR位点不仅可用于法医人类学，同时也可用于群体种系关系的研究。

Objective To investigate the genetic structure of X chromosome in Mongolia, Ewenki, Elunchun and Daweer in Inner Mongolia. Methods Nine short tandem repeat （STR） markers on the X chromesome（DXS6789, DXS101, DXS8378, DXS7132, DXS7133, DXS7423, DXS6804, DXS6799 and HPRTB） were analyzed in the four populations from Inner Mongolian （ Mongol, Ewenki, Oroqen and Daur） for their genetic diversity, forensic suitability and possible genetic affinities of the populations. Frequencies and other parameters of forensic interest were computed. Results The results revealed that the nine markers described here have a moderate degree of variability in the population groups. And there are significant differences in the genetic variability among the populations. Genetic distance and cluster analyses show very low genetic distance between Mongol and Han （Xi＇ an） communities. The results based on genetic distance analyses are consistent with earlier studies based on linguistic as well as immigration history and origin of these populations. Conclusion The nine STR loci studied here were found not only useful in studying genetic variations between populations but also suitable for human identity testing.