Genetic affinity between Ningxia Hui and eastern Asian populations revealed by a set of InDel loci

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.

Landscape Impacts on Ecosystem Service Values Using the Image Fusion Approach

The landscape is a complex mosaic of physical and biological patches with infrastructures, cultivable lands, protected ecosystems, water bodies, and many other landforms. Varying land-use changes are vulnerable to the world and need the mitigation and management of landforms to achieve sustainable development, which without proper oversight, may lead to habitat destruction, degradation, and fragmentation. In this study, we quantify the land-use and land-cover (LULC) changes using downscaled satellite imagery and assess their effects on ecosystem services (ES) and economic values in Ningxia Province, China. Various landscape metrics are derived to study the pattern and spatial configuration over 15 years (2005–2020), in which the landscapes are evolving. The impact of LULC change in various ES is analyzed using ecosystem service values (ESV) and validated with a sensitivity index. Finally, the level of urban sprawl (US) due to overpopulation is established using Renyi’s entropy. Using Landsat 8′s Operational Land Imager (OLI) datasets, we downscaled the MODIS data of 2005, 2010, 2015, and 2020 to prepare the LULC map through a rotation forest algorithm. Results demonstrate that water bodies, woodlands, and built-up landscapes increased in their spatial distribution over time and that there was a decrease in farmlands. Results further suggest that the connectivity and uniformity of the landscape pattern improved in the later period due to several plans formulated by the government with a slight improvement in landscape diversity. Overall ESV get improved, while LULC classes such as farmland and water bodies have decreased and increased ESV, respectively, and a sensitivity analysis is used to test the reliability of ESV on LULC classes. The level of US is 0.91 in terms of Renyi’s entropy, which reveals the presence of a dispersion of settlements in urban fringes. The simulated US for 2025 shows urbanization is more severe over a prolonged time and finally the impacts of the US in ESV are analyzed. Using an interdisciplinary approach, several recommendations are formulated to maintain the ESV despite rapid LULC changes and to achieve sustainable development globally.

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.

Significant East Asian Affinity of the Sichuan Hui Genomic Structure Suggests the Predominance of the Cultural Diffusion Model in the Genetic Formation Process

The ancestral origin and genomic history of Chinese Hui people remain to be explored due to the paucity of genome-wide data. Some evidence argues that an eastward migration of Central Asians gave rise to modern Hui people, which is referred to as the demic diffusion hypothesis; other evidence favors the cultural diffusion hypothesis, which posits that East Asians adopted Muslim culture to form the modern culturally distinct populations. However, the extent to which the observed genetic structure of the Huis was mediated by the movement of people or the assimilation of Muslim culture also remains highly contentious. Analyses of over 700 K SNPs in 109 western Chinese individuals (49 Sichuan Huis and 60 geographically close Nanchong Hans) together with the available ancient and modern Eurasian sequences allowed us to fully explore the genomic makeup and origin of Hui and neighboring Han populations. The results from PCA, ADMIXTURE, and allele-sharing-based f-statistics revealed a strong genomic affinity between Sichuan Huis and Neolithic-to-modern Northern East Asians, which suggested a massive gene influx from East Asians into the Sichuan Hui people. Three-way admixture models in the qpWave/qpAdm analyses further revealed a small stream of gene influx from western Eurasians into the Sichuan Hui people, which was further directly confirmed via the admixture event from the temporally distinct Western sources to Sichuan Hui people in the qpGraph-based phylogenetic model, suggesting the key role of the cultural diffusion model in the genetic formation of the Sichuan Huis. ALDER-based admixture date estimation showed that this observed western Eurasian admixture signal was introduced into the Sichuan Huis during the historic periods, which was concordant with the extensive western-eastern communication along the Silk Road and historically documented Huis' migration history. In summary, although significant cultural differentiation exists between Hui people and their neighbors, our genomic analysis showed their strong genetic affinity with modern and ancient Northern East Asians. Our results support the hypothesis that the Sichuan Huis arose from a mixture of minor western Eurasian ancestry and predominant East Asian ancestry.

Genetic origins and sex-biased admixture of the Huis

The Hui people are unique among Chinese ethnic minorities in that they speak the same language as Han Chinese (HAN) but practice Islam. However, as the second-largest minority group in China numbering well over 10 million, the Huis are under-represented in both global and regional genomic studies. Here, we present the first whole-genome sequencing effort of 234 Hui individuals (NXH) aged over 60 who have been living in Ningxia, where the Huis are mostly concentrated. NXH are genetically more similar to East Asian than to any other global populations. In particular, the genetic differentiation between NXH and HAN (FST = 0.0015) is only slightly larger than that between northern and southern HAN (FST = 0.0010), largely attributed to the western ancestry in NXH (∼10%). Highly differentiated functional variants between NXH and HAN were identified in genes associated with skin pigmentation (e.g., SLC24A5), facial morphology (e.g., EDAR), and lipid metabolism (e.g., ABCG8). The Huis are also distinct from other Muslim groups such as the Uyghurs (FST = 0.0187), especially, NXH derived much less western ancestry (∼10%) compared with the Uyghurs (∼50%). Modeling admixture history indicated that NXH experienced an episode of two-wave admixture. An ancient admixture occurred ∼1,025 years ago, reflecting the intensive west-east contacts during the late Tang Dynasty, and the Five Dynasties and Ten Kingdoms period. A recent admixture occurred ∼500 years ago, corresponding to the Ming Dynasty. Notably, we identified considerable sex-biased admixture, i.e., excess of western males and eastern females contributing to the NXH gene pool. The origins and the genomic diversity of the Hui people imply the complex history of contacts between western and eastern Eurasians.

Genetic polymorphisms of 44 Y chromosomal genetic markers in the Inner Mongolia Han population and its genetic relationship analysis with other reference populations

Y chromosomal genetic markers in the non-recombining region are commonly used for human evolution research, familial searching, and forensic male differentiation since they strictly follow paternal inheritance. Y chromosomal short tandem repeats (Y-STRs) possess extraordinarily advantages in forensic applications because of their high polymorphisms and special genetic pattern. Here, we assessed the genetic diversities of 41 Y-STRs and three Y chromosomal insertion/deletion (Y-InDels) loci in the Chinese Inner Mongolia Han population; besides, genetic differentiation analyses among the studied Han population and other previously reported populations were conducted based on 27 same Y-STRs. Totally, 425 alleles were observed in 324 Inner Mongolia Han individuals for these Y-markers. Gene diversities of these Y-markers distributed from 0.0306 to 0.9634. The haplotype diversity and discriminatory capacity of these Y-markers in the Inner Mongolia Han population were 0.9999 and 0.98457, respectively. Haplotype resolution comparisons of different Y-marker groups in the studied Han population revealed that higher haplotype resolution could be achieved for these 44 Y-markers. Population genetic analyses of the Inner Mongolia Han population and other reference populations demonstrated that the studied Han population had relatively closer genetic affinities with Northern Han Chinese populations than Southern Han and other minority groups. To sum up, these 44 Y-markers can be utilized as a valuable tool for male differentiation in the Inner Mongolia Han population.

The Genetic Structure of Chinese Hui Ethnic Group Revealed by Complete Mitochondrial Genome Analyses Using Massively Parallel Sequencing

Mitochondrial DNA (mtDNA), coupled with maternal inheritance and relatively high mutation rates, provides a pivotal way for us to investigate the formation histories of populations. The Hui minority with Islamic faith is one of the most widely distributed ethnic groups in China. However, the exploration of Hui's genetic architecture from the complete mitochondrial genome perspective has not been detected yet. Therefore, in this study, we employed the complete mitochondrial genomes of 98 healthy and unrelated individuals from Northwest China, as well as 99 previously published populations containing 7274 individuals from all over the world as reference data, to comprehensively dissect the matrilineal landscape of Hui group. Our results demonstrated that Hui group exhibited closer genetic relationships with Chinese Han populations from different regions, which was largely attributable to the widespread of haplogroups D4, D5, M7, B4, and F1 in these populations. The demographic expansion of Hui group might occur during the Late Pleistocene. Finally, we also found that Hui group might have gene exchanges with Uygur, Tibetan, and Tajik groups in different degrees and retained minor genetic imprint of European-specific lineages, therefore, hinting the existence of multi-ethnic integration events in shaping the genetic landscape of Chinese Hui group.

Forensic characteristic and population structure dissection of Shaanxi Han population in the light of diallelic deletion/insertion polymorphism data

The genetic polymorphisms of diallelic deletion/insertion polymorphic (DIP) loci in the Shaanxi Han population are still not clearly characterized. Herein, allele frequencies and forensic application efficiencies for 30 diallelic DIP loci were investigated in 506 unrelated healthy Han individuals from Chinese Shaanxi province. Based on population data of the same 30 diallelic DIP loci, the genetic differentiations, hierarchical clustering relationships and population architectures among Shaanxi Han and other 50 populations were further dissected through genetic and bioinformatics analyses. Results indicated that most of the 30 diallelic DIP loci were relatively high polymorphisms in the Shaanxi Han population; and there were the genetically intimate relationships between Shaanxi Han and the East Asian populations. In summary, this study provided significant insights into genetic background of Shaanxi Han population, and the multiplex amplification of these 30 diallelic DIP loci was appropriate for forensic individual identification and population genetic research in Shaanxi Han population.

Ancestry Prediction Comparisons of Different AISNPs for Five Continental Populations and Population Structure Dissection of the Xinjiang Hui Group via a Self-Developed Panel

Ancestry informative markers are genetic markers that show distinct genetic divergences among different populations. These markers can be utilized to discern population substructures and estimate the ancestral origins of unknown individuals. Previously, we developed a multiplex system of 30 ancestry informative single nucleotide polymorphism (AISNP) loci to facilitate ancestral inferences in different continental populations. In the current study, we first compared the ancestry resolutions of the 30 AISNPs and the other previously reported AISNP panels for African, European, East Asian, South Asian and American populations. Next, the genetic components of the Xinjiang Hui group were further explored in comparison to these continental populations based on the 30 AISNPs. Genetic divergence analyses of the 30 AISNPs in these five continental populations revealed that most of the AISNPs showed high genetic differentiations between these populations. Ancestry analysis comparisons of the 30 AISNPs and other published AISNPs revealed that these 30 AISNPs had comparable efficiency to other AISNP panels. Genetic relationship analyses among the studied Hui group and other continental populations demonstrated that the Hui group had close genetic affinities with East Asian populations and might share the genetic ancestries with East Asian populations. Overall, the 30 AISNPs can be used to predict the bio-geographical origins of different continental populations. Moreover, the obtained genetic data of 30 AISNPs in the Hui group can further enrich the extant reference data, which can be used as reference data for ancestry analyses of the Hui group.