重庆汉族人群X染色体4个STR基因座遗传多态性的研究

发布时间：2018-07-03 18:55

  本文选题：重庆 + 汉族　； 参考：《重庆医科大学》2010年硕士论文

【摘要】： 背景及目的:微卫星序列是重复单位长度为2～6bp的重复序列,即短串联重复序列(short tandem repeats,STR)或简单重复序列(simple sequence repeats, SSRs)。STR是目前法医学DNA分析中最常见的一类遗传标记,因其在人类基因组中分布广泛,分型技术简单、快速,可重复性高,是目前国内外法医学个体识别和亲子鉴定的主要发展方向。近年来,常染色体和Y染色体STR基因座已得到广泛的研究与应用,但人类X染色体STR因其独特的遗传方式,在法医学一些特殊亲权鉴定及个人识别案件中有一定的优势。本实验通过对重庆地区汉族人群无关个体X染色体上DXS7132、DXS6789、HPRTB、DXS8378四个STR位点的等位基因与基因型的观察,调查其在重庆汉族群体中的遗传多态性,探讨其法医学意义。 方法:随机选取重庆地区(籍贯为重庆市)无血缘关系、健康汉族个体211名(女120名,男91名)静脉血500ul,EDTA抗凝,用Chelex-100法提取基因组DNA后,-20℃保存。PCR扩增体系为20ul,分别加入各个基因座特异性引物,设定不同的退火温度,约30个循环后,得到含等位基因片段的扩增产物。6!聚丙烯酰胺凝胶电泳,硝酸银染色分型。四个基因座等位基因频率、基因型频率采取直接计数法,X 2检验女性样本Hardy-Weinberg平衡吻合度检验,用Promega公司的软件Powerstates1.2版本和Exel表计算杂合度(Heterozygosity,H),匹配概率(probability of matching, Pm),个人识别力(probability of discrimination power , DP),非父排除率(exclusion probability of paternity, PE)、多态信息总量(polymorphism information content, PIC)等群体遗传学指标。 结果:在重庆汉族120名女性和91名男性无关个体中,DXS7132检出7个等位基因11～17,DXS6789检出10个等位基因15～24,HPRTB检出9个等位基因9～17,DXS8378检出6个等位基因9～14。X 2检验男女等位基因频率分布无显著性差异。四个基因座在女性个体分别发现有17,31,28,12种基因型,杂合度分别为0.825,0.808,0.769,0.658,X 2检验女性基因型频率分布均符合Hardy-Weinberg平衡(P0.05)。四个等位基因座DXS7132/DXS6789/HPRTB/DXS8378女性个人识别率分别为0.910,0.955,0.939,0.806;非父排除率分别为0.646,0.615,0.543,0.367。再与不同地区及不同民族的等位基因频率分布进行了比较,发现均有一定的差异。 结论:本研究首次提供了重庆地区汉族人群DXS7132,DXS6789,HPRTB,DXS8378基因座分布多态性数据。四个基因座均具有基因频率分布较好、多态信息量大、个体识别率高的特点,其等位基因分布在不同地区的不同人群中具有差异性。本次研究结果为构建法医DNA数据库和群体遗传学数据库提供了基础数据,为重庆地区开展人类遗传学研究、汉族人群个人识别和亲子鉴定提供了新的遗传标记信息。
[Abstract]:Background & AIM: microsatellite sequences are repetitive sequences with unit length of 2~6bp, that is, short tandem repeats (short tandem repeats) or simple repeats (simple sequence repeats, SSRs). STRs are the most common genetic markers in forensic analysis. Because of its wide distribution in the human genome, simple typing technique, high reproducibility and rapidity, it is the main development direction of forensic individual identification and paternity identification at home and abroad. In recent years, autosomal and Y chromosome STR loci have been widely studied and applied, but human X chromosome STR has some advantages in forensic medicine in some special paternity identification and personal identification cases because of its unique genetic way. In this experiment, the alleles and genotypes of four STR loci of DXS7132FDXS6789HPRTBHXS8378 in unrelated individuals of Han nationality in Chongqing were observed and their genetic polymorphisms in Chongqing Han population were investigated and their forensic significance was discussed. Methods: a total of 211 healthy Han individuals (120 females and 91 males) were randomly selected from Chongqing area (native city of Chongqing) to study the anticoagulant effects of EDTA in venous blood. The genomic DNA was extracted by Chelex-100 method and stored at 20 鈩，

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