Genetic Polymorphism Study Of The Y Chromosome In Pedigree With The Surname Kong And Their Forensic Implications

Objective:Being an ancient surname and with detail genealogy resources, the surname Kong has a clear patrilineal inherited history more than two thousand years, and Y chromosome is also inherited from father to son. So, the male samples from the surname Kong may be a good material which could disclose the relationship between Chinese surname and Y chromosome haplotyes. In a crime scene investigation, taking advantage of Y chromosome genetic markers tested from biological evidence, unidentified bodies and so on, we should, therefore, infer the surname of the suspect and the unidentified bodies, which would have significant mean for the detection of cases. The samples from the surname of Kong which is one of Chinese special genetic resources were selected to study, including12Y-SNPs with high polymorphism in Eastern Asia and17Y-STRs from the Y filer kit. The difference of haplogroups frequency between the samples from surname Kong population and unrelated male population is compared. All this will be useful for exploring the correlation between surname and Y chromosome in forensic applications studies.Methods:255unrelated male blood samples who share the same surname Kong and330unrelated male blood samples obtained randomly were collected. Both samples are blood stain obtained from blood card. Chelex-100and the phenol-chloroform method were adopted to extract DNA. Two multiplex genotyping assays and SNaPshot assay were used to analysis all samples which allows to obtain the Y haplogroups.17Y-STRs were further typed for the surname Kong population samples. The software package Arlequin3.5.1.2and the program Network4.6.1.1were used for data statistical analysis.Results:13haplogroups were observed including C-M130, D-M174, K-R*-M9, O*-M175,O1a-M119, O2al-M95, O3*-M122, O3a*-M324, O3a2*-P201, O3a2b-M7, O3a2c1*-M134, O3a2c1a-M117and Non-M9. The haplogroup frequency difference between the two populations is C-M130(1.96%,9.39%)、D-M174(4.31%,2.42%)、K-R*-M9(1.96%,11.52%)、O*-M175(10.59%,5.15%).O1a-M119(3.92%,7.88%)、O2a1-M95(0.51%,10.30%)、O3*-M122(7.84%,2.42%)、 O3a*-M324(11.77%,14.55%)、O3a2*-P201(10.59%,5.46%)、O3a2b-M7(2.35%,2.73%)、O3a2c1*-M134(14.12%,8.18%)、O3a2c1a-M117(21.57%,14.85%)、 Non-M9(3.92%,5.15%) respectively.196haplotypes in Kong population defined by17Y-STRs locus were obtained and the haplotype diversity is0.9939. Compared the Y-STR mutation rates among all locus, DYS392locus has the highest value in Expected heterozygosities(EH), Polymorphism Information Content(PIC), and its mean distribution among allele11-14. DYS391locus has the lowest value in EH and PIC. DYS458locus has the lowest frequency in allele15(0.0745), etc.14-12-25-28-19-15-12-19-12-11-12-22-12-11-14-10-19is the typical haplotype. Median Joining algorithm and Mismatch Distribution were adopted to analyzed the Y-STR haplotye under haplogroup O3-M122, and the result show that there are two "central star" distribution.Conclusions:This study shows that the haplogroup O3-M122is dominant in Kong population, and the main subhaplogroup under haplogroup O3-M122. is O3a2cla-M117. The genetic polymorphism of Y-STRs among Kong population is better. Combined with Y-SNP and Y-STR analysysing showed that the Kong population experienced complicated genetic exchanges and expansion or continued growth, which has more than one surname origin. Hence, its population genetic structure and historical differences have potential applications in forensic science.