中国汉族群体O3-M122单倍群下游AIMs系统深度挖掘、验证和应用基础研究

The Y chromosome contains the longest non-recombining region in the human genome, making it an informative tool for reconstructing genetic relationship of human populations and paternal lineages, and dating important evolutionary and demographic events. The O3-M122 haplogroup is present with high frequency across many extant East Asian populations and encompass more than 40% of the present Han Chinese in total. However, The fact that insufficient sequencing data of Y chromosomes of human populations lead to lack of test sites of haplogroup O3-M122 downstream, greatly limited the application of Ychromosomal DNA in the field of forensic and molecular anthropology.For this reason,to achieve sufficiently high coverage in the non-recombining regions of Y chromosome (NRY) and an adequate representation of individual samples, we will select 300 males, encompassing only the haplogroups O3-M122 and sequence their nonrepetitive segments of NRY using a capturing specific sequencies by modified oligonucleotide probes. After the further verification of the ancestry informative markers results by sequencing, the final panel of Y HG-O3 AISNP will be developed for the accurate estimation of the source of unkown DNA. Also, we will conduct a comprehensive assessment of this panel on a large routine sample size,and forensic caseworks. Therefore, this study will expand the capacity of Y-STR and Y-SNP databases and refinement the structure of Y lineage tree. Morever, A novel HG-O3 AISNP panel for idividual genetic composition will improve the efficiency and effectiveness of Ychromosome in forensic sciences.

Y染色体是目前筛选祖先信息位点、分析人群遗传结构的最重要遗传标记。O3-M122是中国汉族最为常见的父系类型，目前，由于Y染色体测序数据缺乏，导致O3-M122单倍群的下游测试位点较少,限制了Y-SNP在分子人类学和法医学应用范围。为此，本研究拟通过大样本量检测汉族群体Y-STR和Y-SNP，筛选O3-M122代表性样本，采用Y染色体目标序列捕获测序技术结合微测序深度挖掘、并甄选具有地理和姓氏分辨力的AIM-SNPs，最终构建一组适用于法医学高通量或中通量技术平台分析的Y HG-O3 AISNP panel。本研究的开展一方面可以扩充东亚个体Y-SNP/Y-STR基础数据库的容量，进一步细化Y染色体O3-M122谱系树；另一方面对于法医学中推断未知DNA样本的民族及地理来源具有重要意义，可拓宽Y染色体在法医物证学的应用范围，更好地为法庭科学提供服务。

Y染色体是目前筛选祖先信息位点、分析人群遗传结构的最重要遗传标记。O2-M122是中国汉族最为常见的父系类型，本研究通过大样本量检测汉族群体Y-STR和Y-SNP，筛选单倍群O2-M122 代表性样本300例，根据二代测序数据的分析方法，更新了单倍群O2-M122主干和三个支系O2a1b-IMS-JST002611、O2a2b1a1-M117、O2a2b1a2-F444更加精密的父系Y染色体谱系树，详细描述了各个单倍群下新增的支系和位点，以及更新后的谱系树对进一步的人类学研究的意义，经过更新的东亚人群父系Y染色体谱系树包括>1000个支系以及13,800个Y染色体多态位点。其中包括约8000个骨干位点以及约5,800个私有位点,可广泛应用于东亚地区族群相关的人类进化，法医学，民族学和家族谱系构建等众多领域的研究。本项目深度挖掘、甄选了317个AIM-SNPs，构建了一组适用于法医学高通量技术平台二代测序体系。此外，基于一代测序平台，本项目用等位基因特异性扩增方法依次建立了28个Y-SNP的Oβ复合检测体系和30个Y-SNP的Oγ单倍群复合检测体系。两个中通量体系能稳定检测0.125ng的DNA样本，样本适应性和抗抑制性较好。本项目构建的Y-SNP的复合扩增体系，可以为我国Y-SNP信息的积累提供可靠的技术保障，通过Y-SNP与Y-STR共享单倍群信息，为公安提供更加精准的线索。该体系也可以用于Y-SNP相关的研究调查，为法医学应用提供基础数据。