The application of miniplex primer sets in the analysis of degraded DNA from human skeletal remains

A new set of multiplexed PCR primers has been applied to the analysis of human skeletal remains to determine their efficacy in analyzing degraded DNA. These primer sets, known as Miniplexes, produce shorter amplicons (50-280 base pairs (bp)) than standard short tandem repeat (STR) kits, but still utilize the 13 CODIS STR loci, providing results that are searchable on national DNA databases. In this study, a set of 31 different human remains were exposed to a variety of environmental conditions, extracted, and amplified with commercial and Miniplex DNA typing kits. The amplification efficiency of the Miniplex sets was then compared with the Promega PowerPlex 16 system. Sixty-four percent of the samples generated full profiles when amplified with the Miniplexes, while only 16% of the samples generated full profiles with the Powerplex 16 kit. Complete profiles were obtained for 11 of the 12 Miniplex loci with amplicon sizes less than 200 bp. These data suggest smaller PCR amplicons may provide a useful alternative to mitochondrial DNA for anthropological and forensic analysis of degraded DNA from human skeletal remains.     

The utility of whole genome amplification for typing compromised forensic samples

Biological evidence has become invaluable in the crime laboratory; however, it may exist in limited quantity and/or quality. Given this, the ability to amplify total DNA obtained from evidence, in an unbiased manner, would be highly advantageous. Methods for whole genome amplification (WGA) have the potential to fulfill this role, resulting in a virtually unlimited supply of DNA. In the research presented, two WGA methods, improved primer extension preamplification and multiple displacement amplification (MDA), were tested using commercial kits. Control DNA, artificially degraded DNA, and DNA from fresh blood, aged blood, hair shafts, and aged bones underwent WGA, followed by short tandem repeat and mitochondrial DNA analysis. The methods did amplify DNA, but performed poorly on forensically relevant samples; the maximum amplicon size was reduced, and MDA often resulted in extraneous bands following polymerase chain reaction. Taken together, WGA appears to be of limited forensic utility unless the samples are of a very high quality.     

云南怒族X染色体5个STR基因座遗传多态性

目的以云南怒族无关个体为研究对象,调查怒族群体DXS6804、DXS6799、DXS8378、DXS7130、DXS7132基因座的基因频率及基因型频率分布,建立群体遗传数据库。方法用聚合酶链反应(PCR)、变性聚丙烯酰胺凝胶电泳结合银染的方法,检测100名云南怒族个体X染色体上5个STR基因座的重复序列长度变化。结果云南怒族群体5个STR基因座具有遗传多态性,χ2检验表明多态性分布符合Hardy-Weinberg平衡定律。结论云南怒族群体DXS6804、DXS6799、DXS8378、DXS7130和DXS7132基因座,可用于法医学个体识别、亲子鉴定等研究。     

STR滑脱模型的构建及其影响因素

目的探索建立体外STR滑脱模型,研究STR滑脱产生的影响因素,探讨STR的发生机制。方法首先通过全基因组扩增技术—简并寡核苷酸引物PCR(Degenerateoligonucleotide-primedPCR,DOP)对模板DNA样本进行扩增放大,然后以其产物作为后续STR分析的模板,对以上实验过程中的一系列实验条件进行控制,观察滑脱现象的产生情况。结果初步建立了STR的滑脱模型,观察到了STR滑脱现象的发生。结论STR的发生是一系列综合因素作用的结果,DNA模板用量、MgCl2的浓度、DNA聚合酶的性质、样本以及STR的基序组成等因素均可能参与了这一过程。     

天津汉族人群12个Y-STR基因座的遗传多态性

目的　建立天津汉族 2 10名无关男性人群 12个Y STR基因座单倍型分布基础遗传数据库。探讨其法医学应用价值。方法　应用PowerPlex YSystem (PromegeCorporation ,USA)荧光标记复合扩增系统、ABI 310 /377型基因分析仪进行检测 ,统计各基因座的单倍体基因频率 ,计算其GD值即基因差异性 (GeneDiversi ty)。结果　 12个Y STR基因座中共检出 2 0 8种单倍型。其中 ,2 0 6种单倍型均出现 1次 ,2种单倍型出现 2次。GD值在 0 32 5 9～ 0 8810之间 ,累计GD值 (TGD)为 0 9999988。另对 2 8个父性家系调查显示 :同一家系(2～ 7名男性 ) 12个Y STR基因座单倍型一致。结论　天津汉族 12个Y STR基因座多态性分布良好 ,父系遗传稳定 ,适用于法庭科学中的个体识别和亲权鉴定