Objective To investigate the genetic polymorphism and structure of 47 autosomal microhaplotypes in the Han population in Changshu City, Jiangsu Province, and to evaluate the forensic efficiencies and forensic parameters. Methods The DNA library of unrelated individual samples was prepared according to MHSeqTyper47 kit manual and sequenced on the MiSeq FGx platform. Microhaplotype genotyping and sequencing depth statistics were processed using MHTyper. The genetic information of samples was then evaluated. The fixation index and genetic distance between the Jiangsu Changshu population and the reference populations in the 1000 Genomes Project phase 3 (1KG) were calculated, and forensic parameters were evaluated. Results The fixation index and genetic distance between the Han population in Changshu, Jiangsu, and the CHB (Han Chinese in Beijing, China) reference population in 1KG were the lowest. The effective allele number (Ae) of each locus is also the closest between the two populations. The combined matching probability (CMP) of the Changshu Han population is close to the 5 populations of the East Asian reference super -population in 1KG, which is 1.25x10-36, and the combined probability of exclusion reached 0.999 999 999 964 1. Conclusion This study reported the genetic polymorphism and allele frequency of 47 microhaplotypes in a Han population in Changshu City, Jiangsu Province. This information provides a data basis for 47 microhaplotypes in forensic applications. In addition, the polymorphism differences between the 1KG reference population and the Han population in Changshu, Jiangsu were compared, and the genetic structure of 47 microhaplotypes in the Han population in Changshu, Jiangsu was revealed. In general, the reference data of the East Asian super -population in 1KG is more in line with the genetic characteristics of Han population in Changshu, Jiangsu.

Y染色体具有父系遗传的特性.公安机关已建立了Y-STR家系排查方法,用以划定侦查范围、确定犯罪嫌疑人所在的家系.在本文中,技术人员通过Y-STR定位家系,容差推断锁定近亲家系并利用状态一致性(IBS)分析法鉴别全同胞关系,充分挖掘检材分型信息,更好地服务侦查破案,丰富了Y-STR的综合应用策略.

目的 实现以荧光标记复合扩增产物为扩增模板的STR序列多态分型.方法 筛选常用STR分型试剂盒基因座并设计引物,构建常染色体STR复合扩增体系.分别以毛细管电泳(CE)试剂盒GlobalFilerTM、PowerPlex?21和IdentifilerTM Plus的扩增产物为模板,扩增、建库测序及数据分析,评估体系分型准确性及对CE扩增产物的通用性,并与Precision ID GlobalFilerTM NGS STR Panel体系进行比较.结果 该复合扩增体系能够从3款CE试剂盒的扩增产物中获得所有基因座的正确分型和序列多态信息,其体系均衡性和杂合子均衡性亦良好,且均优于Precision ID体系.结论 该复合扩增体系建立了CE技术与二代测序技术之间的桥梁,实现了检材的零利用,能够进一步挖掘荧光标记扩增产物的STR序列多态信息,是对现有技术的提升和有效补充.

目的研究法医学常用Y-STR基因座在中国云南苗族男性个体中的序列多态性.方法采用M48磁珠提取纯化试剂盒提取样本DNA,使用ForenSeqTM DNA Signature Prep试剂盒制备文库,Miseq FGx平台进行测序,ForenSeq Universal Analysis v1.2.1软件进行数据分析,用Arlequin v3.5软件计算各Y-STR基因座相关的统计学参数,将Y-STR基因座长度多态性与序列多态性进行比较.结果108名云南苗族个体中共检出106种单倍型,总体单倍型多样性(HD)和Y-STR分型系统的分辨能力(DC)分别为0.9993和0.9815.24个Y-STR基因座共检出204个基因,基因多样性(gene diversity,GD)值为0.2177～0.9481,15个Y-STR基因座的GD值大于0.6.DYF387S1、DYS390、DYS389II、DYS437、DYS438、DYS448、DYS612基因座存在长度相同的基因核心序列不同的情况.结论该24个Y-STR基因座在云南苗族男性人群中具有丰富的遗传多态性.研究结果可为Y-STR数据库的建立、群体遗传学和法医学实践提供参考.

目的:筛选能有效中和炭疽毒素和抵抗炭疽毒素损伤细胞的CMG2-Fc(炭疽毒素受体Ⅱ-人免疫球蛋白Fc段融合蛋白)突变体.方法:运用FoldX等计算软件分析CMG2与PA晶体学结构,设计能提高CMG2-PA亲和力的突变体分子,并与人IgG1 Fc片段构成融合基因,转染CHO-S细胞并通过亲和层析获得CMG2-Fc突变体蛋白,通过亲和力检测和细胞保护实验分析各突变体中和炭疽毒素能力.结果:筛选并表达了8个CMG2-Fc突变体分子,亲和力实验显示其中E117Q突变可明显提高CMG2-Fc与PA的亲和力(KD=1.35× 10-11 mol/L),细胞保护实验提示E117Q突变能有效提高CMG2-Fc中和炭疽毒素能力(CMG2-Fc(E117Q)的IC50为15 ng/μL,而wtCMG2-Fc的IC50为50 ng/μL).结论:CMG2-Fc(E 117Q)突变体分子可作为拮抗炭疽毒素损伤的炭疽治疗药物分子,进行进一步研究.

探究网线接头上的脱落细胞进行STR分型的可行性及脱落细胞不同的采集方法对STR分型结果的影响.通过比较发现剪取法采集网线接头上的脱落细胞进行STR分型37例中检出12个以上基因座达33例,显著高于擦拭法,得出剪取法采集网线接头上的脱落细胞进行STR分型效果更优的结论.

本文利用苏州市公安系统DNA数据库资源，进行大规模汉族人群的15个基因座的遗传多态性分析。采用AmpFISTR Identiifler试剂盒、AmpFISTR Identiifler Plus试剂盒、AGCU 17+1试剂盒进行扩增，经测序后获得510000名汉族个体15个STR基因座的DNA分型，应用Excel软件计算等位基因的分布频率等群体遗传学数据。在15个STR基因座共检出等位基因344个、基因型1890个。所调查的汉族人群15个基因座具有较好的识别力。

Touch DNA is now often encountered in forensic investigation. Its successful acquisition is often crucial for solving the relevant cases. In this paper, 1025 pieces of touch DNA samples tested in our laboratory since 2012 are reviewed with the purpose to find some regularity. These samples were collected from various electric connectors consisting of mobile phones’ (156 pieces), net cables’ (416 pieces), power cables’ (155 pieces), displays’ (22 pieces), and USBs’ (276 pieces). The DNA was extracted with modified method of silica, amplified with AmpFLSTR? Identifiler? Plus PCR Kit, electrophoresed with ABI3500XL. Data were analyzed with GeneMapper ID-X. The results showed that the detection rate was 93.6% for mobile phones’ connectors, 84.4% for net cables’, 82.0% for power cables’, 95.5% for displays’, and 89.5% for USBs’, with a total detection rate of 87.0% for all the 1,025 pieces of touch DNA samples. The method applied here is suitable to tackle the samples of touch DNA.

目的 通过比较对改良硅珠法提取DNA的灵敏性和稳定性进行评价.方法 样本模板使用9947A(0.1 ng/μL),以30pg为等差,配置10～700pg共24种不同浓度的DNA模板,分别采用常规硅珠法与改良硅珠法提取并纯化模板DNA,在GeneAmp PCR System 9700上进行PCR扩增,ABI 3500XL型荧光分析仪进行电泳检测.结果 与9947A标准品阳性对照比较,采用常规硅珠法检验,24份样本均未获得成功分型;采用改良硅珠法检验,当模板量达到550pg时,即可得到所有基因座的成功分型;模板量达到580pg及以上时,16个基因座图谱峰值均可超过200RFU,分型稳定准确.结论 改良硅珠法提取DNA易于操作,稳定性较好,灵敏度优于常规硅珠法,可在法医微量物证DNA检验中应用.

1 案例资料 1.1 简要案情 2011年10月21日晚,本市发生一起抢劫杀人案,受害人邵某被单刃锐器刺穿心脏和右侧肺脏致失血死亡.10月25日抓获嫌疑人,经现场指认在案发地附近池塘中提取作案刀具遂送检(图1). 1.2 DNA检验 1.2.1 DNA提取 用棉签分别从刀刃、刀柄和刀柄刃结合部(将刀柄刃结合处剪断)三个部位进行擦拭.所提取的检材用硅珠法处理,DNA的提取和纯化参考文献[1].