选择压力对五个少数民族群体HLA-G基因3’非翻译区多态性的影响  

Impact of natural selection on the polymorphism of HLA-G 3tUTR among five ethnic Chinese populations

作　　者：孙浩[1] 孙倩倩[1] 黄铠[1] 林克勤[1] 刘舒媛[1] 杨昭庆[1] 褚嘉祐[1] 黄小琴[1] 

机构地区：[1]中国医学科学院北京协和医学院医学生物学研究所,昆明650118

出　　处：《中华医学遗传学杂志》2016年第4期435-441,共7页Chinese Journal of Medical Genetics

基　　金：中央高校基本科研业务费专项资金协和青年基金（33320140013,3332013085）;国家高技术研究发展计划（863计划）（2012AA021802）;国家自然科学基金（31571304）

摘　　要：目的探讨选择压力与遗传背景对中国5个南北方少数民族群体HLA-G基因3＇非翻译区（untranslatedregions，UTR）多态性的影响。方法采用PCR扩增及DNA测序的方法，对中国3个南方少数民族（仡佬族、水族、傣族）和2个北方少数民族（柯尔克孜族及蒙古族）共432人进行HLA-G基因第8外显子3’UTR区域多态性位点的基因分型，并选择10个中性短串联重复（shorttandemrepeats，STR）多态性位点进行基因分型。结果在蒙古族、柯尔克孜族和仡佬族的HLA-G基因3’UTR区中检测到8个多态性位点，在傣族和水族中检测到7个多态性位点。3’UTR区域的多态性位点在3个南方少数民族群体的观察杂合度大多高于期望杂合度，在北方的两个少数民族群体中，二者的关系是相反的。STR的期望杂合度和观察杂合度的关系均为随机。单倍型Ewens—Watterson中性检测在南方的傣族和水族中有统计学意义。3个南方群体HLA-G基因3’UTR区域多态性构建基因树与群体STR系统发育树有所偏差。结论居住于中国南方的傣族和水族的HLA-G基因3，UTR区域可能受到选择作用，这种选择作用可能由与病原选择所驱动的。Objective To assess the impact of natural selection and genetic background on the polymorphisms of HLA-G 3＇-untranslated regions （UTR） among five ethnic Chinese populations. Methods PCR and DNA sequencing were used to determine the polymorphisms among 432 individuals from the five ethnic populations. Their genetic background was determined by genotyping of 10 short tandem repeats （STRs）. Results Eight variations were identified among Gelao, Mongolian and Kirgiz populations, while only 7 were found in Shui and Dai people. For all 3 southern populations （Gelao, Shui, and Dai）, the observed heterozygosites （Ho） was higher than expected heterozygosities （He）. But this was reversed for the 2 northern populations （Mongolian and Kirgiz）. The Ho and He of the 10 neutral STRs were in random distribution. Ewens-Watterson testing based on haplotypes of the HLA-G 3r UTR has suggested that a natural selection had occurred in the region where Dai and Shui had inhabited, but not in the northern region where Mongolian and Kirgiz population inhabited. Polygenetic trees based on the HLA and STRs were also different. Conclusion The HLA-G 3tUTR of Dai and Shui people who lived in southern China may have subjected to a selection pressure. Based on current knowledge, this pressure may have been driven by a pathogenic selection.

关 键 词：HLA-G基因 3’非翻译区 多态性 自然选择 

分 类 号：R394[医药卫生—医学遗传学]