Forensic characteristics and genetic affinity analyses of Xinjiang Mongolian group using a novel six fluorescent dye-labeled typing system including 41 Y-STRs and 3 Y-InDels

Genetic polymorphism of 27 Y-STR loci in Kazakh populations from Eastern Kazakhstan

BACKGROUND

The establishment of a national haplotype database is important for forensic and genetic applications and requires studying genetic polymorphisms at Y-STR sites. However, the genetic structure of the Eastern Kazakhstan population is poorly characterised.

AIM

To investigate the genetic polymorphisms of 27 Y-STR loci in the Kazakh population from Eastern Kazakhstan and analyse the population genetic relationships of the Eastern Kazakhs with other populations.

SUBJECTS AND METHODS

The Yfiler Plus kit was utilised to genotype 246 healthy, unrelated males from Eastern Kazakhstan. Based on the raw data, haplotype and allele frequencies along with forensic parameters were calculated, and an MDS plot was constructed.

RESULTS

A total of 207 haplotypes were detected, of which 186 were unique. The haplotype diversity and discrimination capacity were 0.997 and 0.841, respectively. Population comparisons showed that Eastern Kazakhs have close genetic relationships with Kazakhs from Xinjiang, China. At the same time, a difference was found between the studied population and the previous one in the same part of Kazakhstan.

CONCLUSIONS

The obtained haplotypes will help to expand the Kazakhstan Y-chromosome reference database and will be useful for future genetic research and forensic applications.

Allelic and haplotypic polymorphisms and paternal genetic analysis of Chinese Shaanxi Han population utilizing a multiplex Y-STR set

BACKGROUND

The analysis of Y chromosomal genetic markers is of great significance in human genetic fields related to male individuals. The Han nationality is the most populous ethnic group. It is critical to investigate the Y-chromosome short tandem repeat (Y-STR) genetic informativeness of Han nationalities in different Chinese regions in order to gain a comprehensive understanding of their paternal genetic relationships and origin.

AIM

To assess the allelic and haplotypic polymorphisms of the novel AGCU Y SUPP STR amplification system containing seven Y-STRs in the maximal dataset of the Y-STR Haplotype Reference Database (YHRD) and 17 newly included Y-STRs, and explore the genetic relationships among the Shaanxi Han population and 12 reference populations from China.

SUBJECTS AND METHODS

A total sample of 220 Han male subjects were obtained from the Shaanxi Province, China, and genotyped by the novel AGCU Y SUPP STR amplification system. Multiplex population genetic analyses derived from the same 16 Y-STR loci were carried out among the Shaanxi Han population and 12 reference populations from China.

RESULTS

The gene diversities (GD) ranged from the maximum value of 0.9609 (DYS385a,b) to the minimum value of 0.5441 (DYS531). Besides, 217 distinct haplotypes were detected wholly in 220 individuals, of which 214 (98.62%) were exclusive. The entire haplotype diversity (HD) and discrimination capacity (DC) were 0.9999 and 0.9864, respectively, while the haplotype match probability (HMP) was 0.0045. Among the reference populations, the obtained results of population genetic analyses revealed that the Shaanxi Han population had the largest genetic distance with the Guangxi Yao group, but the smallest genetic distance with the Hunan Tujia group.

CONCLUSIONS

These Y-STR loci in the AGCU Y SUPP STR amplification system were of high genetic polymorphisms and the amplification system could be used as a prospective complementary tool for forensic application and paternal genetics in the Shaanxi Han population.

Genetic Polymorphism of 27 Y-STR Loci in the Western Kazakh Tribes from Kazakhstan and Karakalpakstan, Uzbekistan

Data on the genetic polymorphism of 27 Y-STR in Kazakhs of the Junior Zhuz has been presented and analyzed in relation to forensic features. A total of 464 representatives of the Western Kazakh tribes of Kazakhstan (Western Kazakhs, n = 405) and Uzbekistan (Karakalpakstan Kazakhs, n = 59) were examined by the Yfiler Plus set. The data are available in the YHRD under accession numbers YA006010 and YA006009. Genetic analysis (AMOVA and MDS) did not show significant differences between the two groups (Kazakhstan and Karakalpakstan Kazakhs) in terms of Y-chromosome diversity. Both groups are characterized by haplogroup C2a1a2 as a founder effect, which dominated two of the three tribes: Alimuly (67%), Baiuly (74.6%), and Zhetiru (25.8%). At the same time, the phylogenetic network for each tribe found its own clusters within C2a1a2. Western Kazakhs and Karakalpakstan Kazakhs present high values of unique haplotypes (84.44% and 96.61%), discrimination capacity (90.37% and 98.30%), and haplotype diversity (0.9991 and 0.9994). A set of 27 Y-STR loci distinguishes closely related individuals within the Western Kazakh tribes quite well. It is suitable for forensic application, and is also optimal for population genetics studies.

Developmental Validation of a Rapidly Mutating Y-STR Panel Labeled by Six Fluoresceins for Forensic Research

The male-specific region of the human Y chromosome is a useful genetic marker for genealogical searching, male inheritance testing, and male DNA mixture deconvolution in forensic studies. However, the Y chromosomal short tandem repeats (Y-STRs) are difficult to distinguish among related males due to their low/medium mutation rate. In contrast, rapidly mutating (RM) Y-STRs exhibit unusually high mutation rates and possess great potential for differentiating male lineages. In this study, we developed a novel Y-STRs multiplex amplification assay of 32 RM Y-STRs by fragment analysis using six dye-labeled technologies (FAM, HEX, TAMRA, ROX, VIG, and SIZ). The development and the validation of the kit were carried out in accordance with the Scientific Working Group guidelines on DNA Analysis Methods. Identical allelic profiles of the 32 RM Y-STRs using a DNA 9948 sample as the positive control could be observed at different concentrations of PCR reagents. Further, the RM Y-STRs did not show cross-reactions with other common animal species, and the developed assay could tolerate interferences from common PCR inhibitors and mixed DNA samples. More importantly, the kit showed relatively high sensitivity and could detect trace DNA samples. Genetic distributions of 32 RM Y-STRs in the Guizhou Han population revealed that these RM Y-STRs showed relatively high genetic diversities. In conclusion, the RM Y-STR assay developed here showed good species specificity, high sensitivity, tolerance to inhibitors, and sample compatibility, which can be viewed as a highly efficient tool with high discrimination capacity for forensic male differentiation.

Comprehensive Insights Into Forensic Features and Genetic Background of Chinese Northwest Hui Group Using Six Distinct Categories of 231 Molecular Markers

The Hui minority is predominantly composed of Chinese-speaking Islamic adherents distributed throughout China, of which the individuals are mainly concentrated in Northwest China. In the present study, we employed the length and sequence polymorphisms-based typing system of 231 molecular markers, i.e., amelogenin, 22 phenotypic-informative single nucleotide polymorphisms (PISNPs), 94 identity-informative single nucleotide polymorphisms (IISNPs), 24 Y-chromosomal short tandem repeats (Y-STRs), 56 ancestry-informative single nucleotide polymorphisms (AISNPs), 7 X-chromosomal short tandem repeats (X-STRs), and 27 autosomal short tandem repeats (A-STRs), into 90 unrelated male individuals from the Chinese Northwest Hui group to comprehensively explore its forensic characteristics and genetic background. Total of 451 length-based and 652 sequence-based distinct alleles were identified from 58 short tandem repeats (STRs) in 90 unrelated Northwest Hui individuals, denoting that the sequence-based genetic markers could pronouncedly provide more genetic information than length-based markers. The forensic characteristics and efficiencies of STRs and IISNPs were estimated, both of which externalized high polymorphisms in the Northwest Hui group and could be further utilized in forensic investigations. No significant departure from the Hardy-Weinberg equilibrium (HWE) expectation was observed after the Bonferroni correction. Additionally, four group sets of reference population data were exploited to dissect the genetic background of the Northwest Hui group separately from different perspectives, which contained 26 populations for 93 IISNPs, 58 populations for 17 Y-STRs, 26 populations for 55 AISNPs (raw data), and 109 populations for 55 AISNPs (allele frequencies). As a result, the analyses based on the Y-STRs indicated that the Northwest Hui group primarily exhibited intimate genetic relationships with reference Hui groups from Chinese different regions except for the Sichuan Hui group and secondarily displayed close genetic relationships with populations from Central and West Asia, as well as several Chinese groups. However, the AISNP analyses demonstrated that the Northwest Hui group shared more intimate relationships with current East Asian populations apart from reference Hui group, harboring the large proportion of ancestral component contributed by East Asia.

Forensic characteristics and population construction of two major minorities from southwest China revealed by a novel 37 Y-STR loci system

Y-chromosome short tandem repeats (Y-STRs) have become important supplementary evidence in forensic science. Nowadays, the Y-chromosome STR haplotype reference database (YHRD) contains abundant Y-STR haplotype data from all over the world, while haplotype data of Guizhou Miao and Tujia are scarce. Hence, genetic polymorphisms of 37 Y-STRs were investigated in 446 unrelated males (206 Miao males and 246 Tujia males) residing in Guizhou Province. A total of 206 and 242 unique haplotypes with the highest diversity value of 0.9665 and 0.9470 were obtained. The heatmap, multidimensional scaling (MDS), the unweighted pair-group method with arithmetic means (UPGMA) tree and principal component analysis (PCA) based on the genetic distance (Rst) value within our studied populations and other 26 populations indicated that population structures follow the boundary of the continent. Guizhou Miao and Guizhou Tujia populations have intimate relationships with East Asian populations, especially the geographically close, similar history and the same language family populations.

Developmental validation of the Yfiler Platinum PCR Amplification Kit for forensic genetic caseworks and databases

Y chromosome kits are successfully applied in cases where human biological material exists. With the development of genotyping ability, more Y chromosomal markers are needed for finer identification of male individuals and lineages. In this study, a developmental validation of a newly emerged Y chromosome kit that combines two different kinds of markers: 38 Y-STRs and 3 Y-indels are conducted. The results show that this kit has high sensitivity when there is a small amount of DNA (125 pg), more than one male (minor:major = 1:7), or a mixture of males and females (male:female = 125pg:1875pg), inhibited substances (800 μM hematin and more than 1600 ng/μL humic acid). The kit exhibits high precision level with a standard deviation of allele size no more than 0.14 nt. Locus DYS481 shows the largest stutter rate, with three stutters per true allele. Population samples are well identified (MP of 0.001106), and mutations can be observed in father-son pairs (46 mutations in 70 pairs, 10 in locus DYS627). Out of all the population samples, 13.2% belong to haplogroup M117-O2a2b1a1, with their ethnic group being Han Chinese. The results show that this kit can improve the performance of identifying male individuals, obtaining more unique haplotypes (increasing from 894 to 918 of 1000 male samples) and higher discrimination capacity (increasing from 0.942 to 0.955) in this study compared to previous widely used Yfiler Plus kit. Besides, it gives information about their paternal lineages in forensic genetic casework and genealogical database construction.

Forensic characteristics and genetic affinity analyses of Xinjiang Mongolian group using a novel six fluorescent dye-labeled typing system including 41 Y-STRs and 3 Y-InDels

BACKGROUND

Y-chromosomal genetic marker haplotypes of individuals can define the paternal kinship or genealogies to which they belong and further provide clues for forensic individual identifications. Studying the genetic structure of the Mongolian group will help to bring to light the Mongolian ethnic origin, and explicate the genetic affinities among the studied and compared populations. Some forensic scientists have studied the genetic background of the Mongolian group based on different molecular genetic markers. These studies were of very great reference significance for the Mongolian group genetic research, whereas the investigation of Y-STR haplotype data in the Xinjiang Mongolian group is still insufficient.

METHODS

Genetic characteristics of 182 unrelated healthy male Mongolian individuals were revealed by 41 Y-chromosomal short tandem repeat and 3 insertion/deletion molecular genetic markers. Furthermore, analyses of molecular variance programs, multi-dimensional scaling plots, and phylogenetic tree reconstructions were operated to explore the genetic relationships of the Xinjiang Mongolian group with comparative 23 populations from China and 33 populations from worldwide nations.

RESULTS

The genetic diversity values ranged from 0.0641 (rs771783753) to 0.9502 (DYF387S1). A total of 165 distinct haplotypes were identified, of which 150 (90.91%) were unique. The discrimination capacity, match probability, and haplotype diversity of 44 loci were 0.9066, 0.0067, and 0.9988, respectively. Additionally, the Mongolian group had the most intimate relationship with Gansu Dongxiang (RST  = 0.0165), followed by HulunBuir Mongolian (RST  = 0.0187), Inner Mongolia Daur (RST  = 0.0202) as well as other three minority ethnic groups from the Xinjiang region (RST  < 0.05) in all compared Chinese populations, and clustered together with the majority of Asian populations in a worldwide scale.

CONCLUSIONS

Consequently, the 44 loci could be well applied in forensic applications of the Mongolian group. The haplotypes available in here made new contributions to the existing population genetic information and would be of great value in population studies.