Combining Y-SNPs With Y-STRs To Reconstruct Human Paternal Line

The Y chromosome exhibits strict paternal inheritance,with the characteristics of non-recombination,and mutation is the only source of diversity.Descendants of the same ancestor have inherited the same Y chromosome mutation and have accumulated new mutations in evolution.Due to the small size of the effective population,it is easy to form regional specific haplogroups,and the regular geographical distribution of Y haplogroups makes Y chromosome the most powerful research tool for human population genetics,which can reveal the migration routes and Population genetic relationships,and can reconstruct the paternal evolutionary history of the population.The Y chromosome can also realize the family investigation function,which facilitates the search of the criminal suspect,and is gradually paid attention to by the application of forensic medicine.There are two main types of mutations on the Y chromosome:single nucleotide polymorphism(SNP)and short tandem repeat(STR).The mutation rate of Y-SNPs is low(about 2×10^-8 times/generation),and this mutation can accurately reconstruct its evolution process.The mutation rate of Y-STRs is relatively fast(about 3.17×10^-3 times/generation).The mutation method is based on the ancestor's tandem repeat times as the median.Each Y-STR locus has diversity.Y-SNPs and Y-STRs can effectively cooperate to calculate the differentiation time of the population.The use of two genetic markers,Y-SNPs and Y-STRs,in forensic medicine can enable traceability screening of unknown samples,Y-SNPs can achieve the delineation of family relationships on a large scale,and Y-STRs can achieve small size within a wide range of families.Scale of recent genetic relationships.This study attempts to build a paternity ancestral screening model based on Y-SNPs and Y-STRs data,and conduct family inspections on unknown samples of forensic medicine.This screening method can be used to search for suspects and kinship screening of unknown remains.Compared with the current method of using Y-STRs alone in forensics,adding Y-SNPs can quickly find the appropriate family information,which greatly avoids many interference factors.This study used Y-SNPs and 7 Y-STRs core loci that divided East Asian population-specific haplogroups to carry out trace analysis of 4409 unrelated individuals.The study found that in the absence of Y-SNPs genetic markers as haplogroup remarks,the clustering of Y-STRs is more complicated.Many different groups and individuals without the same haplogroup can also come together to form many discriminants.Interfering factors.When the genetic marker information of Y-SNPs is added,basically all individuals under the same haplogroup in the same group can be brought together,which can achieve accurate family investigation.The effective cooperation of Y-SNPs and Y-STRs can quickly lock the screening scope,and can greatly improve the screening efficiency,and realize the accuracy of screening while reducing the work intensity and saving time.