藏族群体7个Y-STR基因座及单倍型的遗传多态性

目的调查藏族Y染色体7个STR基因座及单倍型的遗传多态性。方法应用PCR、变性聚丙烯酰胺凝胶电泳结合银染显色分型技术,检测67例藏族男性DNA样品。结果在DYS393、DYS389Ⅰ、DYS19、DYS390、DYS389Ⅱ、DYS392等6个基因座中共检出25个等位基因,DYS385基因座检出22个等位基因组,频率分布在0.0149～0.5075之间,各基因座DP值分布在0.5075～0.8991之间,以DYS385基因座最高。由7个基因座组成的YH6系统单倍型有51种,DP值为0.9887,DYS393与DYS389Ⅱ基因座等位基因少,推测藏族群体在进化过程中可能发生过瓶颈事件。结论上述7个STR基因座属于高鉴别能力基因座,单倍型具有很高的遗传多态性。     

武汉汉族人群D20S85和D6S477基因座遗传多态性调查

目的对武汉地区280名汉族无关个体的D20S85和D6S477位点遗传多态性进行调查,研究其在法医学检验中的应用价值。方法应用PCR和PAGE技术进行分型检验。结果分别检出10个、9个等位基因,获得各等位基因在该地区汉族人群分布频率,基因型频率分布符合Hardy-Weinberg平衡。两位点的DP值分别为0.9085、0.9127。结论D20S85和D6S477是法医学中重要的遗传标记。     

复合扩增STR位点片段长度多态性的研究

本文介绍了以三个短串联重复序列（STR）位点为基础的复合扩增进行个体识别的技术。其特点是在同一扩增体系内对彼此独立的三个STR位点，即HUMTH01[AATG]nHUMFABP[AAT]nHUMARA[AGC]n进行复会扩增，扩增产物用聚丙烯酰胺凝胶电泳分离。经研究发现这三个STR位点具有高度多态性，扩增产物分子量在190～310bP之间，各位点等位基因数分别为6、9、16个，杂合度78．2％、85，0％、89．0％，个体识别率0．918、0．960、0．905，其累积的个体识别率达0．9997，高于pMCT118等位点，且扩增时间短，操作简便，为法医物证检验提供了一种高效的个体识别手段。     

SNP Miniplexes for Individual Identification of Random‐Bred Domestic Cats

Phenotypic and genotypic characteristics of the cat can be obtained from single nucleotide polymorphisms (SNPs) analyses of fur. This study developed miniplexes using SNPs with high discriminating power for random‐bred domestic cats, focusing on individual and phenotypic identification. Seventy‐eight SNPs were investigated using a multiplex PCR followed by a fluorescently labeled single base extension (SBE) technique (SNaPshot^®). The SNP miniplexes were evaluated for reliability, reproducibility, sensitivity, species specificity, detection limitations, and assignment accuracy. Six SNPplexes were developed containing 39 intergenic SNPs and 26 phenotypic SNPs, including a sex identification marker, ZFXY. The combined random match probability (cRMP) was 6.58 × 10^?19 across all Western cat populations and the likelihood ratio was 1.52 × 10¹⁸. These SNPplexes can distinguish individual cats and their phenotypic traits, which could provide insight into crime reconstructions. A SNP database of 237 cats from 13 worldwide populations is now available for forensic applications.     

中国28个省/区汉族人群41个STR基因座多态性数据分析

目的调查分析中国28个省/区汉族人群41个STR基因座的遗传多态性,为相关研究和鉴定提供全面科学的基础数据。方法收集28个省/区汉族9 126名无关个体血样本,采用Global FilerTM、AGCU EX-22和AGCU 21+13种试剂盒,进行41个STR基因座分型,统计各基因座等位基因分布和遗传学参数,并对各数据之间进行差异性检验。结果中国28个省/区汉族人群41个基因座分别检出8~76个等位基因,各基因型分布经正和检验,除SE33等7个基因座外,均符合Hardy-Weinberg平衡定律。遗传学参数分析显示,41个基因座中SE33等21个属高鉴别力、高杂合度、高信息量,其余20个属中等高度多态性基因座。部分省份等位基因频率分布数据之间有显著性差异(P0.05),各省与全国综合数据之间则无差异(P0.05)。结论本文调查结果证实41个STR基因座均具有较强的个体识别能力,获得的数据可为法医学应用和筛选适合中国汉族人群基因座等研究和实践提供科学的基础数据。     

广东地区汉族人群VEGF基因5′端SNP位点遗传多态性

目的调查广东地区汉族人群VEGF基因5′端SNP位点的遗传多态性,为法医学应用及群体遗传学研究提供基础数据。方法 DNA微测序技术SNaPshot分析184例广东地区无关个体VEGF基因5′端4个SNP位点(rs699947、rs1570360、rs833061、rs2010963)的遗传多态性。应用PowerMarker v3.25软件进行统计分析。结果 184例广东地区汉族无关个体VEGF基因5′端4个SNP位点基因分布均符合Hardy-Weinberg平衡(P0.05),每个位点均检出3种基因型。rs833061和rs699947位点紧密连锁。共检出6种单倍型,其中C-G-T-C、C-G-T-G、A-A-C-G、A-G-C-G频率均10%,为主要单倍型。rs699947、rs833061、rs2010963位点的个人识别率为0.583~0.634,非父排除率为0.133~0.144;4个SNP构成单倍型的个人识别率为0.868,非父排除率为0.438。结论广东地区汉族人群VEGF基因5′端序列呈现出高度遗传多态性,可作为个人识别和亲权鉴定的遗传学指标,同时可用于相关疾病关联分析。     

FTA卡在微量血痕DNA多态性分析中的应用

目的探索FTA卡样本DNA最小检出量及同一FrA卡样本进行多项目检测的可行性。方法制作含有不同浓度DNA丌A卡,使用Identifiler试剂盒进行检验;对同一rrA卡样本先后使用Identifiler、Y-filer试剂盒进行扩增及线粒体高变区HVI区测序,使用ABl3130测序仪检测各扩增产物。结果载有0．5ngDNA的FTA卡扩增产物即可正确分型,对同一血痕样本使用不同试剂盒检验,均可清晰正确判型,线粒体高变区HVI区测序图清晰,且各检验结果均与对照一致。结论载有0．5ngDNA的FTA卡扩增产物可用于DNA分型检测,FTA卡对DNA结合较稳定,可用于多项目检测。     

Recovery and STR amplification of DNA from RFLP membranes

Restriction fragment length polymorphism (RFLP) techniques were utilized in the forensic DNA community until the mid 1990s when less labor-intensive polymerase chain reaction short tandem repeat (PCR STR) techniques became available. During the transition from RFLP technology to PCR-based STR platforms, a method for comparing RFLP profiles to STR profiles was not developed. While the preferred approach for applying new technology to old cases would be to analyze the original biological stain, this is not always possible. For unsolved cases that previously underwent RFLP analysis, the only DNA remaining may be restriction cut and bound to nylon membranes. These studies investigate several methods for obtaining STR profiles from membrane bound DNA, including removal of bound DNA with bases, acids, detergents, various chemicals, and conventional cell extraction solutions. Direct multiplex STR amplification of template in the membrane-bound state was also explored. A partial STR profile was obtained from DNA that was recovered from an archived membrane using conventional extraction buffer components, indicating promise for recovering useful STR information from RFLP membranes that have been maintained in long-term frozen storage.     

Mitochondrial DNA control region polymorphism in the population of Alagoas state, north-eastern Brazil

The sequences of the two hypervariable (HV) segments of the mitochondrial DNA (mtDNA) control region were determined in 167 randomly selected, unrelated individuals living in the state of Alagoas, north-eastern Brazil. One hundred and forty-five different haplotypes, associated with 139 variable positions, were determined. More than 95% of the mtDNA sequences could be allocated to specific mtDNA haplogroups according to the mutational motifs. Length heteroplasmy in the C-stretch HV1 and HV2 regions was observed in 22 and 11%, respectively, of the population sample. The genetic diversity was estimated to be 0.9975 and the probability of two random individuals presenting identical mtDNA haplotypes was 0.0084. The most frequent haplotype was shared by six individuals. All sequences showed high-quality values and phantom mutations were not detected. The diversity revealed in the mitochondrial control region indicates the importance of this locus for forensic casework and population studies within Alagoas, Brazil.     

Spatial and temporal influences on bacterial profiling of forensic soil samples

Bacterial content may be helpful in differentiating forensic soil samples; however, the effectiveness of bacterial profiling depends on several factors, including uniqueness among different habitat types, the level of heterogeneity within a habitat, and changes in bacterial communities over time. To examine these, soils from five diverse habitats were tested over a 1 year period using terminal restriction fragment length polymorphism (TRFLP) analysis. Soil samples were collected at central locations monthly, and 10 feet in cardinal directions quarterly. Similarity indices were found to be least related among habitats, while the greatest bacterial similarities existed among collection locations within a habitat. Temporally, however, bacterial content varied considerably, and there was substantial overlap in similarity indices among habitats during different parts of the year. Taken together, the results indicate that while bacterial DNA profiling may be useful for forensic soil analysis, certain variables, particularly time, must be considered.