Genetic structure and forensic characterisation of 36 Y-chromosomal STR loci in Hmong-Mien-speaking Miao population

Forensic efficiency and population genetic construction of Guizhou Gelao minority from Southwest China revealed by a panel of 23 autosomal STR loci

Short tandem repeats (STRs) are the most common genetic markers in forensic and human population genetics due to their high polymorphism, rapid detection, and reliable genotyping. To adapt the rapid growth of forensic DNA database and solve problems in disputed cases, a panel of 23 autosomal STR loci with high discriminating ability was constructed recently. The Tai-Kadai-speaking Gelao is the most ancient indigenous minority in Guizhou province, however, the forensic efficiency and population genetic structure remain poorly explored. Here, 490 Guizhou Gelao individuals from Southwest China were genotyped with the panel of 23 STRs using the Huaxia Platinum Kit. A total of 265 alleles were screened. The combined discrimination power and the combined probability of paternity were 0.9999 and 0.9999, respectively. This indicated the 23 loci had higher discrimination power in Guizhou Gelao and could be applied to forensic practice. Comprehensive population structures with reference populations from China and abroad using the neighbour-joining phylogenetic tree (N-J tree), multidimensional scaling, principal component analysis and heatmap demonstrated that Guizhou Gelao was genetically closer to Guizhou Han than other populations. Moreover, our results showed that a complex phylogenetic model was influenced by ethnic, geographic, and linguistic factors.

Key points

The first batch of genetic data for 23 autosomal STRs in 490 Geolao individuals from Guizhou was provided.The 23 STR panel can afford high genetic polymorphisms and discrimination power and can be efficiently applied to forensic practice in Guizhou Gelao population.A complex phylogenetic model influenced by ethnic, geographic, and linguistic factors was uncovered.

The maternal phylogenetic insights of Yunnan Miao group revealed by complete mitogenomes

The Miao group is one of the representative Hmong-Mien-speaking populations and primarily scattered in southern China and Southeast Asia, which has experienced massive migrations in history and thus forms distinctive evolutionary genetics. Yet, the genetic explorations of Miao group are relatively limited based on complete mitochondrial genome (mitogenome), especially for the Miao group from Yunnan Province (YNM). Here, we sequenced complete mitogenomes of 132 Miao individuals from Yunnan Province using massively parallel sequencing method. Total 132 Miao individuals could be allocated to 119 various haplotypes, which were mainly dominated by haplogroups prevalent in southern East Asia (B, F, M7 and R9), and rarely occupied by northern lineages (A, D, G and M8). In order to dissect the genetic background of YNM more comprehensively, we introduced 99 published population data with 7135 complete mitochondrial sequences for population genetic comparisons. YNM exhibited closer genetic relationships with Hmong-Mien, Tai-Kadai, Sino-Tibetan and Austroasiatic populations, especially for Hmong-Mien populations; we further speculated that Miao group might have certain direct or indirect gene exchanges with ancient Baiyue groups. Several maternal lineages, such as B5a1c1a, F1g1, B4a5 and D4e1a3, were found to be specifically shared by YNM and other Hmong-Mien populations, and these matrilineal expansions occurred roughly during the Neolithic period. Eventually, according to the population dynamic analyses of YNM, the population size began to emerge recovery ∼1-0.5 kya after a long-term population reduction ∼1-5 kya, during which the B5a1c1a haplogroup manifested relatively apparent lineage expansion.

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.

Genome-wide allele and haplotype-sharing patterns suggested one unique Hmong-Mein-related lineage and biological adaptation history in Southwest China

BACKGROUND

Fine-scale genetic structure of ethnolinguistically diverse Chinese populations can fill the gap in the missing diversity and evolutionary landscape of East Asians, particularly for anthropologically informed Chinese minorities. Hmong-Mien (HM) people were one of the most significant indigenous populations in South China and Southeast Asia, which were suggested to be the descendants of the ancient Yangtze rice farmers based on linguistic and archeological evidence. However, their deep population history and biological adaptative features remained to be fully characterized.

OBJECTIVES

To explore the evolutionary and adaptive characteristics of the Miao people, we genotyped genome-wide SNP data in Guizhou HM-speaking populations and merged it with modern and ancient reference populations via a comprehensive population genetic analysis and evolutionary admixture modeling.

RESULTS

The overall genetic admixture landscape of Guizhou Miao showed genetic differentiation between them and other linguistically diverse Guizhou populations. Admixture models further confirmed that Miao people derived their primary ancestry from geographically close Guangxi Gaohuahua people. The estimated identity by descent and effective population size confirmed a plausible population bottleneck, contributing to their unique genetic diversity and population structure patterns. We finally identified several natural selection candidate genes associated with several biological pathways.

CONCLUSIONS

Guizhou Miao possessed a specific genetic structure and harbored a close genetic relationship with geographically close southern Chinese indigenous populations and Guangxi historical people. Miao people derived their major ancestry from geographically close Guangxi Gaohuahua people and experienced a plausible population bottleneck which contributed to the unique pattern of their genetic diversity and structure. Future ancient DNA from Shijiahe and Qujialing will provide new insights into the origin of the Miao people.

Genomic Insights Into the Unique Demographic History and Genetic Structure of Five Hmong-Mien-Speaking Miao and Yao Populations in Southwest China

Southern China was the original center of multiple ancestral populations related to modern Hmong-Mien, Tai-Kadai, Austroasiatic, and Austronesian people. More recent genetic surveys have focused on the fine-scale genetic structure and admixture history of southern Chinese populations, but the genetic formation and diversification of Hmong-Mien speakers are far from clear due to the sparse genetic sampling. Here, we reported nearly 700,000 single-nucleotide polymorphisms (SNPs) data from 130 Guizhou Miao and Yao individuals. We used principal component analysis, ADMIXTURE, f-statistics, qpAdm, phylogenetic tree, fineSTRUCTURE, and ALDER to explore the fine-scale population genetic structure and admixture pattern of Hmong-Mien people. The sharing allele patterns showed that our studied populations had a strong genetic affinity with ancient and modern groups from southern and southeastern East Asia. We identified one unique ancestry component maximized in Yao people, which widely existed in other Hmong-Mien-speaking populations in southern China and Southeast Asia and ancient samples of Guangxi. Guizhou Hmong-Mien speakers harbored the dominant proportions of ancestry related to southern indigenous East Asians and minor proportions of northern ancestry related to Yellow River farmers, suggesting the possibility of genetic admixture between Hmong-Mien people and recent southward Sino-Tibetan-related populations. Furthermore, we found a genetic substructure among geographically different Miao and Yao people in Leishan and Songtao. The Yao and Miao people in Leishan harbored more southern East Asian ancestry, but Miao in Songtao received more northern East Asian genetic influence. We observed high mtDNA but low Y-chromosome diversity in studied Hmong-Mien groups, supporting the role of sex-specific residence in influencing human genetic variation. Our data provide valuable clues for further exploring population dynamics in southern China.

Inferring the population structure and admixture history of three Hmong-Mien-speaking Miao tribes from southwest China based on Genome-wide SNP genotyping

BACKGROUND

Hmong-Mien speaking Miao, also called Hmong, is the sixthlargest ethnic group in mainland China. However, the fine-scale genetic profiles and population history of Miao populations in southwest China, especially in Guizhou province, remain uncharacterised due to a scarcity of samples of genome-wide data from different tribes.

AIM

To further investigate the population substructure and admixture history of the Guizhou Miao minority.

SUBJECTS AND METHODS

We collected 29 samples from three Miao tribes of Guizhou province in southwest China and genotyped about 700,000 genome-wide SNPs of each sample. We analysed newly generated data in together with published modern/ancient East Asian populations datasets via a series of population genetic methods, including principal component analysis (PCA), ADMIXTURE, Fst, TreeMix, f-statistics, qpWave, and qpAdm.

RESULTS

PCA and ADMIXTURE results showed that the three studied Guizhou Miao groups consistently fell on the Hmong-Mien-related genetic cline and were relatively genetically homogeneous, displayingd a genetic affinity with neighbouring Tai-Kadai speaking populations such as Dong. These results were further confirmed by the observed genetic clade in Fst, TreeMix, outgroup-f₃ -statistics, and f₄ -statistics. Furthermore, f₄ -based allele sharing patterns illustrated that compared with Hunan Miao in central China, Guizhou Miao shared more alleles with Hmong-Mien-speaking Vietnam Hmong and Tai-Kadai-speaking CoLao, Dong, while exhibiting less northeast Asian-related ancestry. Admixture-f₃ and f₄ statistics revealed the North-South admixture pattern for the studied Guizhou Miao. A qpAdm-based two-way admixture model further revealed that the studied Guizhou Miao harboured 44%∼55.4% indigenous Austronesian-speaking Atayal-related ancestry and 44.6%∼56% Late Neolithic Yellow River farmer-related ancestry.

CONCLUSIONS

The population structure within Hmong-Mien-related populations showed a geographic correlation. Hmong-Mien speaking Hunan Miao, Guizhou Miao, and Vietnam Hmong presented closer genetic relationships although they dwelt in different regions, suggesting the preservation of the original Hmong-related genetic diversity. The results based on genome-wide SNPs data generally matched the migration history for the Miao population. Our study contributes to a better knowledge of Miao populations and the population structure in southwest China.

The Y-STR landscape of coastal southeastern Han: Forensic characteristics, haplotype analyses, mutation rates, and population genetics

The Y-STR landscape of Coastal Southeastern Han (CSEH) living in Chinese southeast areas (including Guangdong, Fujian, and Zhejiang provinces) is still unclear. We investigated 62 Y-STR markers in a reasonably large number of 1021 unrelated males and 1027 DNA-confirmed father-son pairs to broaden the genetic backgrounds of CSEH. In total, 85 null alleles, 121 off-ladder alleles, and 95 copy number variants were observed, and 1012 distinct haplotypes were determined with the overall HD and DC values of 0.999974 and 0.9912. We observed 369 mutations in 76 099 meiotic transfers, and the average estimated Y-STR mutation rate was 4.85 × 10^-3 (95% CI, 4.4 × 10^-3 -5.4 × 10^-3 ). The Spearman correlation analyses indicated that GD values (R² = 0.6548) and average allele sizes (R² = 0.5989) have positive correlations with Y-STR mutation rates. Our RM Y-STR set including 8 candidate RM Y-STRs, of which DYS534, DYS630, and DYS713 are new candidates in CSEH, distinguished 18.52% of father-son pairs. This study also clarified the population structures of CSEH which isolated in population-mixed South China relatively. The strategy, SM Y-STRs for familial searching and RM Y-STRs for individual identification regionally, could be applicable based on enough knowledge of the Y-STR mutability of different populations.

Insights From Y-STRs: Forensic Characteristics, Genetic Affinities, and Linguistic Classifications of Guangdong Hakka and She Groups

Guangdong province is situated in the south of China with a population size of 113.46 million. Hakka is officially recognized as a branch of Han Chinese, and She is the official minority group in mainland China. There are approximately 25 million Hakka people who mainly live in the East and North regions of China, while there are only 0.7 million She people. The genetic characterization and forensic parameters of these two groups are poorly defined (She) or still need to be explored (Hakka). In this study, we have genotyped 475 unrelated Guangdong males (260 Hakka and 215 She) with Promega PowerPlex^® Y23 System. A total of 176 and 155 different alleles were observed across all 23 Y-STRs for Guangdong Hakka (with a range of allele frequencies from 0.0038 to 0.7423) and Guangdong She (0.0047–0.8605), respectively. The gene diversity ranged from 0.4877 to 0.9671 (Guangdong Hakka) and 0.3277–0.9526 (Guangdong She), while the haplotype diversities were 0.9994 and 0.9939 for Guangdong Hakka and Guangdong She, with discrimination capacity values of 0.8885 and 0.5674, respectively. With reference to geographical and linguistic scales, the phylogenetic analyses showed us that Guangdong Hakka has a close relationship with Southern Han, and the genetic pool of Guangdong Hakka was influenced by surrounding Han populations. The predominant haplogroups of the Guangdong She group were O2-M122 and O2a2a1a2-M7, while Guangdong She clustered with other Tibeto-Burman language-speaking populations (Guizhou Tujia and Hunan Tujia), which shows us that the Guangdong She group is one of the branches of Tibeto-Burman populations and the Huonie dialect of She languages may be a branch of Tibeto-Burman language families.

Genetic structure and forensic characterization of 36 Y-chromosomal STR loci in Tibeto-Burman-speaking Yi population

BACKGROUND

Male-specifically inherited Y-STRs have been widely used in population genetics and forensic investigations.

METHODS

We genotyped and analyzed Y chromosome haplotypes of 408 unrelated Tibeto-Burman-speaking Yi male individuals from Guizhou using Goldeneye® Y-PLUS kit. Population comparisons between the Guizhou Yi and 67 reference groups were performed via the AMOVA, MDS, and phylogenetic relationship reconstruction.

RESULTS

A total of 389 alleles and 396 haplotypes could be detected, and the allelic frequencies ranged from 0.0025 to 0.9875. The haplotype diversity, random match probability, and discrimination capacity values were 0.9999, 0.0026, and 0.9900, respectively. The gene diversity (GD) of 36 Y-STR loci in the studied group ranged from 0.0248 (DYS645) to 0.9601 (DYS385a/b). Our newly genotyped Yi samples show a close affinity with other Tibeto-Burman speaking groups in China and Southeast Asia.

CONCLUSIONS

The population stratification was almost consistent with the geographic distribution and language-family, both among Chinese and worldwide ethnic groups. Our data may provide useful information for paternal lineage in the forensic application and population genetics, as well as evidence for archaeological and historical research.