Multi-InDel 遗传标记在中国亚人群结构分析及族源推断中的法医学研究

Ancestry inference classifies the individual from which the forensic sample comes into a specific group, narrowing the investigate scope in the police investigation, providing clues for the casework detecting and offering evidence for the judicial judgment. More powerful ancestry informative markers (AIMs) are needed for complicated population structure analysis and ancestry inference implementation, since little reference data is available for the highly admixed population in China. Multi-InDel markers imply more plentiful genetic information by combining the population-specific inheritance patterns with the merits of AIM-InDels. This kind of novel genetic marker demonstrates potential power in previous studies of population structures, serving the purpose of understanding human evolution history and population differentiation in a dynamic perspective. It is expected to provide a scientific and effective solution for forensic ancestry inference. In this study, we plan to analyze the whole-genome sequencing data in the public database using bioinformatic methods to screen Multi-InDel markers for population stratification studies. The candidate loci are further selected through population genetic survey on samples from Han, Tibetan, Mongolian and Uyghur in China to find ethnic-specific length polymorphisms. Additionally, standardized profiling and analyzing methods as well as high-throughput detecting flow are expected to be designed on the basis of veracity. Various statistical methods will be adopted to make comprehensive and in-depth argument on the power of ancestry inference. And system evaluation will be made to assess the feasibility of these genetic markers to be employed in forensic practice, providing scientific data and theoretical basis for forensic use.

族源推断通过将检材来源个体归类到某特定人群，在刑侦现场调查中缩小排查范围，为侦破案件提供线索，为司法审判提供证据。中国人群混杂程度高，可借鉴数据少，还需探寻更加高效的祖先信息遗传标记用于复杂人群结构分析及族源推断应用。Multi-InDel遗传标记在人群差异InDels的基础上叠加连锁交换的遗传特征。前期研究显示，Multi-InDels具有复杂人群分析鉴别潜能，有望为法医族源推断提供科学有效的解决途径。本项目对公共数据库中的全基因组测序数据进行生物信息学分析，结合中国汉族、藏族、蒙古族和维吾尔族人群样本进行群体遗传学调查，甄选出民族特异性Multi-InDels。对分型分析方法进行标准化，在保证准确性的基础上，设计较高通量的检测分析方法，采用多种统计学分析方法对族源推断效能展开全面而深入的论证，进而对其法医学实践潜能进行评估。为中国不同民族族源推断的法医学实践提供理论依据和数据基础。

族源推断通过将检材来源个体归类到某特定人群，在刑侦现场调查中缩小排查范围，为侦破案件提供线索，为司法审判提供证据。中国人群混杂程度高，可借鉴数据少，还需探寻更加高效的祖先信息遗传标记用于复杂人群结构分析及族源推断应用。Multi-InDel遗传标记在人群差异InDels的基础上叠加连锁交换的遗传特征，具有复杂人群分析鉴别潜能，有望成为法医族源推断实践的有效工具。本项目通过对公共数据库中的全基因组测序数据进行生物信息学分析，结合东亚地区不同居住地人群样本的群体遗传学调查，甄选出人群特异性Multi-InDels。建立基于毛细管电泳平台的检测分析体系，对分型分析方法进行标准化，在保证准确性的基础上，提高检测通量，节省样本用量，以满足DNA质量和/或数量有限的法医学检材的检测需求。进一步对建立的检测体系进行基于SWGDAM标准的一系列验证，以确保其在法医学实践中的应用效能。此外，采用多种统计学分析方法对该体系的族源推断效能展开全面而深入的论证，进而对其法医学实践潜能进行评估。在此基础上，通过对比分析不同的机器学习算法，探索可以灵活适用于各种法医族源推断遗传标记的判别方式，并对其判别效能进行全面的评估，为更加精细的人群结构分析奠定理论依据和数据基础，为遗传特征相似、居住环境相近的人群的族源推断提供法医学实践的可能，为司法刑事案件的侦破提供科学手段。