高分辨Y-SNP-STR共检测在复杂家系搜索和父系溯源中的法医学探索研究

基于高分辨Y染色体遗传标记进行未知个体家系搜索是法医学研究前沿之一。然而，案发现场检材与参比父系有少数Y-STR不一致时，判断参比父系是否包含嫌疑人家系或重新定位家系搜索范围极具困难。为解决上述问题，本项目拟开展基于Y-SNP-STR共检测的探索性研究：①基于全基因组测序数据解析中国主要族群父系遗传结构，识别新系谱信息Y-SNP构建中国主要族群精细Y染色体谱系树，利用多重校正计算模型估算各节点分化时间并绘制中国主要族群Y染色体演化时间框架；②基于高密度芯片数据探索中国主要族群父系单倍群分布模式，识别不同群体的奠基者父系；③基于ISOGG、YFull及本项目识别的系谱信息位点甄选中国主要族群特异性Y-SNP，构建法医实践适用的“法医学谱系树”；④甄选适用于中国主要族群的中低突变和快突变Y-STR，构建高分辨Y-SNP-STR二代测序共检测体系，为法医家系搜索和父系生物地理祖源推断提供新技术。

The pedigree search of biological samples in the scene of a crime based on high-resolution typing technology for Y-chromosomal markers is one of the frontiers of scientific research for forensic genetics. The application of Y-STR to forensic pedigree search has achieved great success. However, when there is no Y-STR haplotype match between the crime scene sample and the reference paternal lineage samples, it is extremely difficult to determine whether the reference paternal lineages contain the suspect family or to relocate the geographic regions of pedigree search. To solve the problems above, we will carry out forensic exploratory research based on combined typing of high-resolution Y-SNP-STR: ①To analyze the paternal genetic structure of major Chinese ethnic groups and identify new lineage informative Y-SNPs based on whole-genome sequencing data, construct the Y-chromosomal phylogenetic tree of the major Chinese ethnic groups and apply a multi-corrected computational model to estimate the splitting times; ②To explore the population and geographic distribution specificity of paternal haplogroups of major Chinese ethnic groups based on high-density microarray data, and identify the paternal founding lineages of different populations; ③To select the specific Y-SNPs for major Chinese ethnic groups based on the lineage informative markers provided by ISOGG, YFull, and this project, and construct a “forensic phylogenetic tree” suitable for forensic practice; ④To use the diversity-driven and mutation-driven approaches to select slowly-mutating, moderately-mutating, and rapidly-mutating Y-STRs with highly polymorphic in major Chinese populations, and develop high-resolution Y-SNP-STR co-typing system based on next-generation sequencing platform to provide new technologies for forensic pedigree searches and paternal biogeographic ancestry inference.