Improving the regional Y-STR haplotype resolution utilizing haplogroup-determining Y-SNPs and the application of machine learning in Y-SNP haplogroup prediction in a forensic Y-STR database: A pilot study on male Chinese Yunnan Zhaoyang Han population

Comprehensive analyses of genetic diversities and population structure of the Guizhou Dong group based on 44 Y-markers

Background

The non-recombining region of the human Y chromosome (NRY) is a strictly paternally inherited genetic marker and the best material to trace the paternal lineages of populations. Y chromosomal short tandem repeat (Y-STR) is characterized by high polymorphism and paternal inheritance pattern, so it has been widely used in forensic medicine and population genetic research. This study aims to understand the genetic distribution of Y-STRs in the Guizhou Dong population, provide reference data for forensic application, and explore the phylogenetic relationships between the Guizhou Dong population and other comparison populations.

Methods

Based on the allele profile of 44 Y-markers in the Guizhou Dong group, we estimate their allele frequencies and haplotype frequencies. In addition, we also compare the forensic application efficiency of different Y-STR sets in the Guizhou Dong group. Finally, genetic relationships among Guizhou Dong and other reference populations are dissected by the multi-dimensional scaling and the phylogenetic tree.

Results

A total of 393 alleles are observed in 312 Guizhou Dong individuals for these Y-markers, with allele frequencies ranging from 0.0032 to 0.9679. The haplotype diversity and discriminatory capacity for these Y-markers in the Guizhou Dong population are 0.99984 and 0.97440, respectively. The population genetic analyses of the Guizhou Dong group and other reference populations show that the Guizhou Dong group has the closest genetic relationship with the Hunan Dong population, and followed by the Guizhou Tujia population.

Conclusions

In conclusion, these 44 Y-markers can be used as an effective tool for male differentiation in the Guizhou Dong group. The haplotype data in this study not only enrich the Y-STR data of different ethnic groups in China, but also have important significance for population genetics and forensic research.

Comprehensive insights into the genetic background of Chinese populations using Y chromosome markers

China is located in East Asia. With a high genetic and cultural diversity, human migration in China has always been a hot topic of genetics research. To explore the origins and migration routes of Chinese males, 3333 Chinese individuals (Han, Hui, Mongolia, Yi and Kyrgyz) with 27 Y-STRs and 143 Y-SNPs from published literature were analysed. Our data showed that there are five dominant haplogroups (O2-M122, O1-F265, C-M130, N-M231, R-M207) in China. Combining analysis of haplogroup frequencies, geographical positions and time with the most recent common ancestor (TMRCA), we found that haplogroups C-M130, N-M231 and R1-M173 and O1a-M175 probably migrated into China via the northern route. Interestingly, we found that haplogroup C*-M130 in China may originate in South Asia, whereas the major subbranches C2a-L1373 and C2b-F1067 migrated from northern China. The results of BATWING showed that the common ancestry of Y haplogroup in China can be traced back to 17 000 years ago, which was concurrent with global temperature increases after the Last Glacial Maximum.

Population data and phylogenetic analysis of 37 Y-STR loci in the Hui population from Yunnan Province, Southwest China

Background: Previous studies of the genetic polymorphism of the Y-chromosomal short tandem repeat (Y-STR) of Huis were focused on the northwest of China. However, the population genetic characteristics of Chinese Hui residing in Yunnan province, Southwest China, remain unclear.Aim: To provide genetic data for 37 Y-STRs in the Chinese Hui population of Yunnan province, as well as to investigate population genetic relationships between the Chinese Hui and another 26 populations from China and neighbouring countries.Subjects and methods: 326 unrelated healthy male individuals were genotyped using the Goldeneye^TM Y Plus PCR Amplification Kit. Genetic relationships between different populations were analysed using YHRD's AMOVA tools.Results: A total of 279 haplotypes were detected, out of which 244 were unique. The overall haplotype diversity (HD) and discrimination capacity (DC) were 0.9989 and 0.8611, respectively. The gene diversity (GD) ranged from 0.0544 (DYS645) to 0.9656 (DYS385).Conclusions:  The population comparison indicated that Muslim populations (Hui, Salar, and Uighur) showed significant genetic affinity than other populations. Our results could be applied in forensic practice and population genetic studies.

Genetic polymorphisms and phylogenetic characteristics of Tibeto-Burman-speaking Lahu population from southwest China based on 41 Y-STR loci

BACKGROUND

Male sex-linked Y-chromosome short tandem repeats (Y-STRs) have been widely used in forensic cases and population genetics research. At present, the forensic-related Y-STR data in the Chinese Lahu population are still poorly understood.

AIM

To enrich the available Y-STR data of this Chinese minority population and investigate its phylogenetic relationships with other reported populations.

SUBJECTS AND METHODS

The genetic polymorphisms of 41 Y-STR loci were analysed in 299 unrelated healthy Lahu male individuals from Southwest China. Phylogenetic analyses were performed by multidimensional scaling analysis and neighbor-joining phylogenetic tree construction.

RESULTS

A total of 379 alleles were observed at the 41 Y-STR loci. The allele frequencies ranged from 0.0033 to 0.9666. The genetic diversity values ranged from 0.0653 to 0.9072. A total of 254 different haplotypes of the 41 Y-STR loci were observed in 299 individuals. The values of haplotype diversity, haplotype match probability, and discrimination capacity were 0.9987, 0.0047, and 0.8495, respectively. The phylogenetic analysis indicated that the Tibeto-Burman-speaking Lahu population showed a close genetic relationship with the Yunnan Yi population.

CONCLUSIONS

The haplotype data of the present study can enrich the forensic databases of this Chinese minority population and will be useful for population genetics and forensic DNA application.

Genetic diversity of 23 Y-STR loci of the Lisu ethnic minority residing in Chuxiong Yi Autonomous Prefecture, Yunnan province, Southwest China

BACKGROUND

The Lisu group is a unique minority in Yunnan province. However, there is a lack of Y-STR population data for Chinese Lisu and the genetic structure of the Lisu group and other populations is unclear.

AIM

To provide genetic data for 23 Y-STRs in the Chinese Lisu population from Chuxiong Yi Autonomous Prefecture, as well as to analyse population genetic relationships between Chinese Lisu ethnic minority and other reference groups.

SUBJECTS AND METHODS

423 unrelated healthy Lisu males were genotyped using the PowerPlex® Y23 system. Forensic parameters were calculated according to the previously published studies. Genetic structure analysis among Chinese Lisu and other populations was conducted using the YHRD's AMOVA tools.

RESULTS

Gene diversity (GD) ranged from 0.2,466 (DYS438) to 0.8,945 (DYS385a/b) among the 23 Y-STR loci. According to haplotype analysis, 323 different haplotypes were obtained, out of which 271 were unique. The haplotype diversity (HD) and discrimination capacity (DC) were 0.9,977 and 0.7,636, respectively. MDS plot indicated that the Chuxiong Lisu group is genetically related to the Yunnan Yi group.

CONCLUSIONS

This is the first report on Y-STR population data for the Chinese Lisu population. These data would be valuable for forensic applications.

Phylogenetic analyses of 41 Y-STRs and machine learning-based haplogroup prediction in the Qingdao Han population from Shandong province, Eastern China

BACKGROUND

Known for its rich history and culture, Qingdao is a typical symbol of Chinese maritime culture. Its unique genetic landscape has aroused interest among geneticists and forensic scientists. However, the genetic landscape of Qingdao has never been uncovered.

AIM

This investigation intends to provide light on Qingdao's paternal genetic diversity and its evolutionary connections to other Han subgroups.

SUBJECTS AND METHODS

The genetic polymorphisms of 41 Y-chromosomal short tandem repeat (STR) loci in the Qingdao Han were investigated using SureID^® PathFinder Plus Kit. Phylogenetic studies were performed using genotype data from 52 East Asian groups at 23 common Y-STR loci. A multidimensional scaling plot and cladogram were constructed. Linear Discriminant Analysis (LDA) was carried out for predicting categories among the Han people. The k-nearest neighbour (kNN) algorithm was utilised to designate Y-SNP haplogroups for each haplotype.

RESULTS

The Qingdao Han were genetically far from the Tibeto-Burman populations and close with the Han people from northern China. LDA indicated a deep integration among the present-day Han people. By the kNN model, the predicted O2a2 and O2a1 were shown to be the predominant Y-SNP haplogroups.

CONCLUSIONS

This study would be helpful for reconstructing the patrilineal history in China and establishing a more comprehensive Y-STR database.

Forensic Analysis and Genetic Structure Construction of Chinese Chongming Island Han Based on Y Chromosome STRs and SNPs

Y-chromosome short tandem repeat (Y-STR) and Y-chromosome single nucleotide polymorphism (Y-SNP) are genetic markers on the male Y chromosome for individual identification, forensic applications, and paternal genetic history analysis. In this study we successfully genotyped 38 Y-STR loci and 24 Y-SNP loci of Pudong Han (n = 689) and Chongming Han (n = 530) in Shanghai. The haplotype diversity of the Y filer platinum genotyping system was the highest in the Han population in the Pudong area of Shanghai (0.99996) and Chongming Island (0.99997). The proportion of unique haplotypes was 97.10% (Pudong) and 98.49% (Chongming), respectively. The multidimensional scaling analysis and phylogenetic analysis were performed according to the genetic distance Rst, which was calculated based on the Y-STR gene frequency data. Moreover, we made a comparison on the frequency distribution analysis and principal component analysis of haplogroups in both populations. As a result, Shanghai Pudong Han, Chongming Island Han, and Jiangsu Han were determined to have a strong genetic affinity. The haplogroup distribution characteristics of the Pudong Han and Chongming Han populations were similar to those of the southern Han population. The results of haplotype network analysis showed that Jiangsu Wujiang Han and Jiangsu Changshu Han had more paternal genetic contributions to the formation of Shanghai Pudong Han and Chongming Island Han. Through the joint analysis of SNPs and STRs, this study deeply analyzed the paternal genetic structure of the Pudong Han and Chongming Han populations. The addition of Y-SNP haplogroups to forensic applications can provide information for pedigree investigation.