Y染色体遗传标记在法医学中的应用

Application of Y Chromosome Genetic Markers in Forensic Science

Y染色体为男性特有,具有父系遗传的特点,其非重组区域的遗传标记,如短串联重复序列(Y-STR)和单核苷酸多态性(Y-SNP)已广泛用于法医学、人类学和遗传学等领域。在性侵犯案件中,应用常染色体STR有时难以将男女混合斑中的男性成分检出,而Y-STR可作为识别男性嫌疑人的有效标记。目前全国各地的Y库建设如火如荼,也正是因为Y-STRs在家系排查中起到了不容小觑的作用。Y-STR相比Y-SNP具有更高的突变率,因此在涉及男性的亲缘关系鉴定及家系排查过程中,要注意该基因座是否发生了突变,避免错误地否定其亲缘关系。快速突变基因座(RM Y-STR)由于突变率较高而在男性个体识别中具有更大的优势。Y-SNPs具有突变率低、分布广等特点,Y-SNPs通过单倍群来重建男性谱系,因此在祖先推断及研究人类迁徙史方面有重要意义。

With the advantage of the presence of non-recombining regions,Y chromosome polymorphisms,such as short tandem repeats(Y-STRs)and single-nucleotide polymorphisms(Y-SNPs),have been widely used in the fields of forensic science,anthropology and genetic genealogy.In sexual assault cases,it is sometimes difficult to detect male components in mixed stains using autosomal STRs,while Y-STR can be used as a valid marker to identify male suspects.At present,the construction of the Y chromosome database in all parts of the country is in full swing,which is exactly because Y-STRs has played a role in the investigation of the family searching.Y-STR has a higher mutation rates than Y-SNP.Therefore,in the process of paternity testing and family searching involving males,it is necessary to pay attention to whether the locus has been mutated to avoid erroneous denial of its kinship.The rapid mutation locus(RM Y-STR)has a greater advantage in human identification due to the higher mutation rate.Specifically,Y-SNPs are used to reconstruct male lineages through hierarchically-arranged allelic sets known as haplogroups,and their continent-specific characteristics enable researchers to infer the biogeographic ancestry of an individual through the haplogroup identification.In summary,this paper reviews the application of Y-STR and Y-SNP of Y chromosome genetic markers in forensic science.