Forensic characteristics and phylogenetic analysis of both Y-STR and Y-SNP in the Li and Han ethnic groups from Hainan Island of China

Hainan Island is the southernmost and smallest Chinese province, isolated from the mainland. The Li and Han ethnic groups account for over 98% of the population on the island. However, the Li ethnic group is an indigenous community of Hainan Island, with great differences in culture, language and origin with respect to the Han, the largest ethnic group. Here, we studied these two ethnic groups from the perspective of the Y-chromosome single nucleotide polymorphisms (Y-SNPs) and short tandem repeats (Y-STRs) to unravel their forensic and phylogenetic characteristics. A total of 302 unrelated male samples from the Li and Han ethnic groups in Hainan Island were genotyped by a combination of three separate typing systems (next-generation sequencing and pyrosequencing for the Y-SNPs and capillary electrophoresis for the Y-STRs), a previously developed high-resolution panel containing 141 Y-SNPs and 27 Y-STRs. The haplotype diversity of the Li ethnic group reached 0.9997, and 49 terminal haplogroups were observed in the Li and Han ethnic groups. Haplogroup O1b1a1a1a1a1b-CTS5854 was the most predominant haplogroup, including 44.12% of Li individuals. Median-joining trees showed little gene flow between the Li and Han individuals, as well as between the Li and other ethnic groups in Hainan Island. Our results indicated that 1) in contrast with the Han ethnic group, a low degree of genetic diversity was observed in the Li ethnic group; 2) there was limited gene flow between the Li and Han ethnic groups; and 3) founder effect was identified in the Li ethnic group in Hainan Island.     

Genetic polymorphism of both 29 Y-STRs and 213 Y-SNPs in Han populations from Shandong Province,China

Genetic markers on the Y chromosome, including short tandem repeats (Y-STRs) and single nucleotide polymorphisms (Y-SNPs), are used widely in forensic genetics. Both Y-STR-based haplotypes and Y-SNP-based haplogroups provide information on a population’s genetic structure, which is useful for the identification of individuals. However, there are few studies on these two types of genetic markers in the various Chinese populations. In this study, 284 Han individuals from four prefecture-level cities in Shandong Province (Binzhou, Dezhou, Heze, and Weihai) were genotyped by 29 Y-STRs (from our previous study) and 213 Y-SNPs (self-designed for the Haplogroup O2 Y-SNP panel). Haplogroup O was the most predominant among the four cities. The highest haplogroup diversity (0.9745) was observed in the Heze population, with a discrimination capacity (DC) value of 0.5625. The haplotype diversity and DC values of the Binzhou and Heze populations were 1.0000. Furthermore, genetic differences were observed between the coastal and inland cities; the results of their statistical analysis are presented herein.     

Forensic characteristics and genetic analysis of both 27 Y-STRs and 143 Y-SNPs in Eastern Han Chinese population

Y-chromosome short tandem repeat (Y-STR) and Y-chromosome single nucleotide polymorphism (Y-SNP) frequency distributions provide resources for assessment of male population stratification among world-wide populations. Currently, the Y-STR Haplotype Reference Database (YHRD) contains numerous Y-chromosome haplotype profiles from various populations and countries around the world. However, for many of the recently discovered and already phylogenetically mapped Y-SNPs, the population data are scarce. Herein, the typing of 27 Y-STRs (Yfiler Plus) and 143 Y-SNPs (self-designed Y-SNP panel) was performed on 1269 unrelated males from 11 Han Chinese populations. Haplogroup O-M175 was the most predominant haplogroup in our Han Chinese data, ranging from 67.34% (Henan Han) to 93.16% (Guangdong Han). The highest haplogroup diversity (0.967056) was observed in Heilongjiang Han, with a discrimination capacity (DC) value of 0.3723. The number of alleles at single-copy loci varied from 2 for DYS391 (Guangdong Han) to 16 for DYS518 (Henan Han). For the majority of the populations (8/11), both the haplotype diversity and DC values are 1.0000. Furthermore, genetic differentiations were observed between Northern and Southern Han Chinese. These genetic differences were mainly reflected in haplogroup distribution and frequency, and they were confirmed by statistical analysis.     

Haplotype analysis of the polymorphic 40 Y-STR markers in Chinese populations

Forty Y-STR loci were analyzed in 1128 males from the following six Chinese ethnic populations: Han (n = 300), Hui (n = 244), Korean (n = 100), Mongolian (n = 100), Uighur (n = 284) and Tibetan (n = 100), utilizing two new generation multiplex Y-STR systems, AGCU Y24 STR and GFS Y24 STR genotyping kits, which allow for the genotyping of 24 loci from a single amplification reaction in each system. The lowest estimates of genetic diversity (below 0.5) correspond to markers DYS391 (0.441658) and DYS437 (0.496977), and the greatest diversity corresponds to markers DYS385a/b (0.969919) and DYS527a/b (0.94676). A considerable number of duplicate and off-ladder alleles were also revealed. Additionally, there were 1111 different haplotypes identified from the total 1128 samples, of which 1095 were unique. Notably, no shared haplotypes between populations were observed. The estimated overall haplotype diversity (HD) was 0.999085, and its discrimination capacity (DC) was 0.970745. An MDS plot based on the genetic distances between populations showed the genetic similarity of the southern Han population to the Northern populations of Hui, Korean, Mongolian and Uighur and a clear genetic departure of the Tibetan population from other populations. For the Y STR markers, population substructure correction was considered when calculating the rarity of the Y STR profile. However, because the haplotype based Fst values are extremely small within the present data (0.000153 with 40 Y-STRs), no substructure correction is required to estimate the rarity of a haplotype comprising 40 markers. In summary, the results of our study indicate that the 40 Y-STRs have a high level of polymorphism in Chinese ethnic groups and could therefore be a powerful tool for forensic applications and population genetic studies.     

Haplotype analysis of the polymorphic 24 Y-STR markers in six ethnic populations from China

Twenty-four Y-STR loci were analysed in 1446 males from the following six Chinese ethnic populations: Guangxi Han (n=600), Gin (n=161), Maonan (n=135), Miao (n=186), Zhuang (n=226) and Yao (n=138) using the AGCU Y24 STR amplification kit. The lowest estimates of genetic diversity (below 0.5) correspond to markers DYS391 (0.4006), DYS438 (0.4300), and DS388 (0.4907), and the greatest diversity corresponds to markers DYS385a/b (0.9636) and DYS527a/b (0.9439). Moreover, there were 1331 different haplotypes identified from the 1446 total samples, of which 1233 were unique. Notably, we observed shared haplotypes between the four ethnic populations (Maonan, Miao, Zhuang, Yao ethnic population), except between the Guangxi Han and Gin population. The estimated overall haplotype diversity (HD) was 0.9997. A multidimensional scaling (MDS) plot based on the genetic distances between populations demonstrates the genetic similarity of the Maonan, Miao and Zhuang populations with genetic distance below 3.0. No substructure correction is required to estimate the rarity of a haplotype comprising 24 markers. In summary, the results of our study indicate that the 24 Y-STRs have a high level of polymorphism in these six Chinese ethnic populations and could therefore be a powerful tool for forensic applications and population genetic studies.     

Population genetics of 30 insertion–deletion polymorphisms in two Chinese populations using Qiagen Investigator® DIPplex kit

Insertion–deletion polymorphisms (INDELs) are short length diallelic polymorphisms caused by the insertion or deletion of several bases. INDEL markers can serve as useful supplementary or stand-alone assays for human identification. The Qiagen Investigator^® DIPplex kit multiplexes 30 autosomal INDELs plus amelogenin for forensic use. The objective of this study was to estimate genetic diversity of 30 INDEL markers in the Han (the largest ethnic group of China, n = 565) and She population (almost the smallest ethnic group of China, n = 119), and to evaluate their usefulness in forensic genetics. In the Han and She, the mean observed heterozygosity values were 0.4133 and 0.3896, and the combined matching probability values were 1.80 × 10⁻¹¹ and 3.17 × 10⁻¹¹, respectively. Furthermore, the allele frequencies for each locus were compared with those in other reported Chinese subpopulations, and the forensic efficacy was compared between this kit and in-house developed INDEL assay. This study demonstrates that the Investigator^® DIPplex kit can be used as a supplementary tool for human identity testing in China.     

A 16-plex Y-SNP typing system based on allele-specific PCR for the genotyping of Chinese Y-chromosomal haplogroups

Y-chromosomal SNP (Y-SNP), with its stable inheritance and low mutation, can provide Supplementary information in forensic investigation. While commonly used Y-chromosomal STR haplotypes show their limitations, typing of Y-SNP would become a powerful complement. In this study, a 16-plex Y-SNP typing system based on allele-specific PCR (AS-PCR) was developed to discriminate four dominant Y-chromosomal haplogroups (C-M130, D-CTS3946, N-M231, and O-M175) and 12 predominant sub-haplogroups of O-M175 (O1a-M119, O1a1a1a-CTS3265, O1b-M268, O1b1a2-Page59, O2-M122, O2a1-L127.1, O2a1b-F240, O2a1b1a1-CTS5820, O2a2-P201, O2a2b1a1-M177, O2a2b1a1a1a-Y17728, O2a2b1a2-F114). A series of experimental validation studies including sensitivity, species specificity, male-female mixture and inhibition were performed. The discrimination of the typing system was preliminarily proved with a haplogroup diversity of 0.9239. Altogether, the Y-SNP typing system based on AS-PCR should be capable of distinguishing China’s dominant Y-chromosomal haplogroups in a rapid and reliable manner, thus can be employed as a useful complement in forensic casework.     

Y chromosome haplogroup diversity in a Mestizo population of Nicaragua

Y chromosome single nucleotide polymorphisms (Y-SNPs) are indispensable markers for haplogroup determination. Since Y chromosome haplogroups show a high specific geographical distribution, they play a major role in population genetics but can also benefit forensic investigations. Although haplogroup prediction methods based on Y chromosome short tandem repeats (Y-STRs) exist and are frequently used, precaution is required in this regard. In this study we determine the Y chromosome haplogroups of a Nicaraguan population using several Y-SNP multiplex reactions. Y chromosome haplogroups have been predicted before, but our results show that a confirmation with Y-SNP typings is necessary. These results have revealed a 4.8% of error in haplogroup prediction based on Y-STR haplotypes using Athey's Haplogroup Predictor. The Nicaraguan Mestizo population displays a majority of Eurasian lineages, mainly represented by haplogroup R-M207 (46.7%). Other Eurasian lineages have been observed, especially J-P209 (13.3%), followed by I-M170 (3.6%) and G-M201 (1.8%). Haplogroup E-P170 was also observed in 15.2% of the sample, particularly subhaplogroup E1b1b1-M35. Finally, the Native American haplogroup Q-M242 was found in 15.2% of the sample, with Q1a3a-M3 being the most frequent.     

Haplotype diversity of 17 Y-chromosome STR loci in Han population from different areas of Sichuan Province,Southwest China

The distribution of 17 Y-chromosome short tandem repeat (STR) loci, included in the AmpFlSTR®Yfiler™ amplification kit, were analyzed in six different samplings (N = 878) from Sichuan, China. Haplotype diversity and discrimination capacity (DC) values were calculated. Pairwise Rst values were evaluated in AMOVA analysis and visualized through multidimensional scaling (MDS). A total of 547 unique haplotypes were detected. The observed haplotype diversity and discrimination capacity were 0.9995 and 0.7745, respectively. The homogeneity of Sichuan Han population was detected when microareas were analyzed. This population exhibited no significant genetic difference to both of the minorities in reference databases, Mongolian and Manchu, which had been through mass ethnic amalgamation with Sichuan Han population in history.     

Distribution of Y-chromosome haplogroups in Serbian population groups originating from historically and geographically significant distinct parts of the Balkan Peninsula

Our study enrolled 1200 Serbian males originating from three geographical regions in the Balkan Peninsula inhabited by Serbs: present-day Serbia, regions of Old Herzegovina and Kosovo and Metohija. These samples were genotyped using the combination of 23 Y-chromosomal short tandem repeats (Y-STRs) loci and 17 Ychromosomal single nucleotide polymorphisms (Y-SNPs) loci for the haplotype and haplogroup analysis in order to characterize in detail Y chromosome flow in the recent history. Serbia’s borders have changed through history, forcing Serbs constantly to migrate to different regions of Balkan Peninsula. The most significant migration waves in the recent history towards present-day Serbia occurred from the regions of Old- Herzegovina and Kosovo and Metohija that lie in the south-west/south. High haplotype diversity and discrimination capacity were observed in all three datasets, with the highest number of unique haplotypes (381) and discrimination capacity (0.97) detected in the samples originating from the present-day Serbia. Haplogroup composition didn’t differ significantly among datasets, with three dominant haplogroups (I-M170, E-P170 and R-M198), and haplogroup I-M170 being the most frequent in all three datasets. Haplogroup E-P170 was the second most dominant in the dataset originating from geographical region of Kosovo and Metohija, whereas haplogroup R-M198 was the second most prevalent in the dataset from historical region of Old Herzegovina. Based on the phylogenetic three for haplogroup I constructed within this study, haplogroup I2a1-P37.2 was the most dominant within all three datasets, especially in the dataset from historical region of Old Herzegovina, where 182 out of 400 samples were derived for SNP P37.2. Genetic distances between three groups of samples, evaluated by the Fst and Rst statistical values, and further visualized through multidimensional scaling plot, showed great genetic similarity between datasets from Old Herzegovina and present-day Serbia. Genetic difference in the haplogroup distribution and frequency between datasets from historical region of Old Herzegovina and from geographical region of Kosovo and Metohija was confirmed with highest Fst and Rst vaules. In this study we have distinguished genetic structure, diversity and haplogroup frequencies within 1200 Serbian males from three datasets, relationships among them as well as with other Balkan and European populations, which is useful for studying recent demographic history.     

Genetic analysis of 17 Y-chromosomal STR loci of Chinese Tujia ethnic group residing in Youyang Region of Southern China

Y-STR haplotype data were obtained in a population sample of 197 unrelated healthy male individuals of Chinese Tujia ethnic minority group residing in an autonomous county of Southern China using 17 Y-chromosome STR markers. A total of 197 haplotypes were identified in the set of Y-STR loci. The overall haplotype diversity for the Tujia population at 17 Y-STR loci was 1.0000 ± 0.0005. Genetic distance was estimated between this population and other 14 Chinese populations including Paiwan and Atayal populations of Taiwan, and Southern Han, Dong, Jing, Miao, Yao, Zhuang, Yi, Maonan, She, Hui, Sala, and Tibetan ethnic groups. The results demonstrated that the 17 Y-STR loci analyzed were highly polymorphic in Tujia ethnic group examined and hence useful for forensic cases, paternity testing, and population genetic studies.     

Mitochondrial diversity in Amerindian Kichwa and Mestizo populations from Ecuador

This study presents mitochondrial DNA (mtDNA) data from 107 unrelated individuals from two of the major ethnic groups in Ecuador: Amerindian Kichwas (n = 65) and Mestizos (n = 42). We characterized the diversity of the matrilineal lineages of these Ecuadorian groups by analyzing the entire mtDNA control region. Different patterns of diversity were observed in the two groups as result of the unique historical and demographic events which have occurred in each population. Higher genetic diversity values were obtained for the Mestizo group than for the Amerindian group. Interestingly, only Native American lineages were detected in the two population samples, but with differences in the haplogroup distribution: Kichwa (A, 49%; B, 3%; C, 8%; and D, 40%) and Mestizo (A, 33%; B, 33%; C, 10%; and D, 24%). Analysis of the complete mtDNA control region proved to be useful to increase the discrimination power between individuals who showed common haplotypes in HVSI and HVSII segments; and added valuable information to the phylogenetic interpretation of mtDNA haplotypes.     

The relationship between positional asphyxia and increasing body mass index

Review of the files of the Pathology section of Forensic Science SA over 17 yrs (January 2003-December 2019) revealed 32 adult cases of positional asphyxia (age range 18–87 years; average 49 years – m:f ratio 3:1). Predisposing/causative conditions were accidents, N = 8, alcohol intoxication N = 7, neurological disease N = 7, drug intoxication N = 5, morbid obesity N = 2, combinations of factors N = 2, and a single homicide N = 1. There was one case with below normal weight (BMI 17.9), with 6 cases having normal weights (BMI range 18.9–24.6, average 22.3), 9 being overweight (BMI range 25.3–29.5, average 27.9), and 16 being obese (BMI range 30–66.2, average 40.9). Only 7 cases (22%) had either under/normal weight compared to 25 (78%) who were overweight/obese (p < 0.05). Increasing body mass appears to be a risk factor to be considered in all forms of positional asphyxia; BMI should, therefore, be routinely taken into account in the forensic evaluation of such cases.     

Y-chromosome diversity of the three major ethno-linguistic groups in the Republic of North Macedonia

A total of 314 individuals representing the three major ethno-linguistic groups (ethnic Macedonians, Albanians and Turks) in the Republic of North Macedonia were analyzed for Y-SNPs and Y-STRs using minisequencing and fragment analysis. The haplogroup composition differed remarkably between the three groups with dominance of haplogroup I2 in ethnic Macedonians (28.1%), E1b in Albanians (35.3%) and J2a (34.9%) in Turks, respectively. The haplotype analysis using the YFilerPlus kit disclosed a significant reduction in diversity values (DC, GD) for the Turkish subgroup compared to the Macedonian and Albanian speaking populations. The Y-STR based population analysis revealed a similarity of ethnic Macedonians with neighboring Serbians and Bulgarians. The same holds true for the Albanian speakers from Macedonia and Albania, whereas the Turkish minority in North Macedonia stands apart from the population in Turkey.     

Mitochondrial DNA sequence analysis of a native Bolivian population

Mitochondrial DNA analysis is very useful for the interpretation of the history of human migration and to estimate the frequency of a haplotype in the forensic context. From a human settlement perspective, La Paz area is greatly interesting since the first planned city of the region is located there. Samples from 110 individuals from La Paz were studied analysing the polymorphisms in the D-loop, hypervariable region I (HVI) and hypervariable region II (HVII) in order to verify the genetic diversity. The aim of this study was to start the creation of a population database in order to obtain the genetic interpopulation variability and classify haplotypes into characteristic haplogroups of South America. A total of 97 different haplotypes were identified, 90 being unique, expressed by 122 polymorphic nucleotide positions. Nucleotide and sequence diversity were estimated to be 0.015 ± 0.0075 and 0.996, respectively. Haplogroup distribution in the samples was 57.27% B4, 19.09% C1, 10.00% A2, 3.64% D1, 2.73% D4h3, 1.82% H, and 0.91% for each of the haplogroups A4, B4c1a, CZ, D4J, M7a and M8/N9b. The rate of length heteroplasmy was 36.36% in HVI and 52.73% in HVII. Phylogenetic analysis reveals proximity to the Korean, Chilean aboriginal, Japanese and Australian populations. The estimated genetic variability of the studied population was high, suggesting an early settlement.     

Phylogenic analysis and forensic genetic characterization of Guizhou Miao tribes from 58 microareas via autosomal STR

Genetic polymorphism of 17 autosomal short tandem repeat (STR) loci, included in the PowerPlex®18D amplification kit, were analyzed in Miao tribes from 58 different sampling microareas (N = 5255) of Guizhou as well as two cities (N = 151) of Hunan, China. Allele frequencies and forensic efficiency parameters were calculated. Moreover, comprehensive population genetic comparisons among 91 nationwide populations and 174 Asian populations were conducted based on raw genotype data and allele frequency data, respectively. Our results of forensic efficiency parameters showed that the panel was a robust tool in forensic individual identification and paternity cases for this population. Genetic affinities were observed among most of the Miao tribes revealed by multidimensional scaling plot, principal component analysis, and neighboring-joining tree. The genetic distance between Miao tribes and Han nationalities were varies by different geographical positions. Some of the Miao tribes were genetically closer to the Hmong-Mien populations living in southeastern contiguous regions and even the Indochina. The result coincided with the migration or reverse migration routes for Miao nationality in modern history. This study of the Miao tribes from plenty of microareas in Guizhou would be useful in reconstructing the population history and establishing a more comprehensive forensic reference database.     

Confirmation of Y haplogroup tree topologies with newly suggested Y-SNPs for the C2, O2b and O3a subhaplogroups

Y chromosome single nucleotide polymorphisms (Y-SNPs) are useful markers for reconstructing male lineages through hierarchically arranged allelic sets known as haplogroups, and are thereby widely used in the fields such as human evolution, anthropology and forensic genetics. The Y haplogroup tree was recently revised with newly suggested Y-SNP markers for designation of several subgroups of haplogroups C2, O2b and O3a, which are predominant in Koreans. Therefore, herein we analyzed these newly suggested Y-SNPs in 545 unrelated Korean males who belong to the haplogroups C2, O2b or O3a, and investigated the reconstructed topology of the Y haplogroup tree. We were able to confirm that markers L1373, Z1338/JST002613-27, Z1300, CTS2657, Z8440 and F845 define the C2 subhaplogroups, C2b, C2e, C2e1, C2e1a, C2e1b and C2e2, respectively, and that markers F3356, L682, F11, F238/F449 and F444 define the O subhaplogroups O2b1, O2b1b, O3a1c1, O3a1c2 and O3a2c1c, respectively. Among six C2 subhaplogroups (C2b, C2e, C2e1*, C2e1a, C2e1b and C2e2), the C2e haplogroup and its subhaplogroups were found to be predominant, and among the four O2b subhaplogroups (O2b*, O2b1*, O2b1a and O2b1b), O2b1b was most frequently observed. Among the O3a subhaplogroups, O3a2c1 was predominant and it was further divided into the subhaplogroups O3a2c1a and O3a2c1c with a newly suggested marker. However, the JST002613-27 marker, which had been known to define the haplogroup C2f, was found to be an ancestral marker of the C2e haplogroup, as is the Z1338 marker. Also, the M312 marker for the O2b1 haplogroup designation was replaced by F3356, because all of the O2b1 haplotypes showed a nucleotide change at F3356, but not at M312. In addition, the F238 marker was always observed to be phylogenetically equivalent to F449, while both of the markers were assigned to the O3a1c2 haplogroup. The confirmed phylogenetic tree of this study with the newly suggested Y-SNPs could be valuable for anthropological and forensic investigations of East Asians including Koreans.     

Sequence polymorphism of the mitochondrial DNA control region in the population of Vojvodina Province,Serbia

In order to generate and establish the database for forensic identification purposes in Vojvodina Province (Serbia), the sequence of the hypervariable regions 1 (HV1) and 2 (HV2) of the mtDNA control region were determined in a population of 104 unrelated individuals from Vojvodina Province, using a fluorescent-based capillary electrophoresis sequencing method. A total of 93 different haplotypes were found, of these 83 mtDNA types were unique, nine haplotypes were shared by two individuals and one haplotype by three individuals. The variation of mtDNA HV1 and HV2 regions was confined to 116 nucleotide positions, of which 72 were observed in the HV1 and 44 in the HV2. A statistical estimate of the results for this population showed the genetic diversity of 0.9977 and the random match probability of 1.18%. Haplogroup H was the most common haplogroup (43.3%). Haplogroups observed at intermediate levels included clusters U (13.5%), T (10.6%), J (8.6%) and W (5.8%).     

Forensic characteristics and phylogenetic analysis of Hubei Han population in central China using 17 Y-STR loci

Currently, the largest national database within the Y chromosome haplotype reference database (YHRD, https://yhrd.org, release 53) is China, which has approximately 38000 Y chromosomal 17-marker (Yfiler) haplotypes. These haplotype profiles derived from the vast majority of Chinese administrative divisions, but no haplotype data was available for Hubei province, which is located in the Central China region. Herein, 429 unrelated male Chinese Han individuals residing in Hubei province were recruited and genotyped with 17 Y-STR loci. 115 alleles were identified with corresponding allele frequencies spanned from 0.0023 to 07506. The gene diversity (GD) values ranged from 0.3988 at DYS438 to 0.9573 at DYS385a/b. A total of 410 distinct haplotypes were obtained with the overall haplotype diversity (HD) and discrimination capacity (DC) was 0.9995 and 0.9557, respectively. Additionally, genetic relationships along administrative (Han Chinese from different provinces) and ethnic divisions (minority ethnic groups) were analyzed using analysis of molecular variance (AMOVA) tests and visualized by multidimensional scaling plots (MDS). The Han ethnicity including the Hubei Han shows a high genetic homogeneity all across China and significant genetic differences existed between the Hubei Han and some ethnic groups, most prominently for the Kazakhs and the Tibetans.