Y-chromosome distributions among populations in Northwest China identify significant contribution from Central Asian pastoralists and lesser influence of western Eurasians

Evolutionary profiles and complex admixture landscape in East Asia: New insights from modern and ancient Y chromosome variation perspectives

Human Y-chromosomes are characterized by nonrecombination and uniparental inheritance, carrying traces of human history evolution and admixture. Large-scale population-specific genomic sources based on advanced sequencing technologies have revolutionized our understanding of human Y chromosome diversity and its anthropological and forensic applications. Here, we reviewed and meta-analyzed the Y chromosome genetic diversity of modern and ancient people from China and summarized the patterns of founding lineages of spatiotemporally different populations associated with their origin, expansion, and admixture. We emphasized the strong association between our identified founding lineages and language-related human dispersal events correlated with the Sino-Tibetan, Altaic, and southern Chinese multiple-language families related to the Hmong-Mien, Tai-Kadai, Austronesian, and Austro-Asiatic languages. We subsequently summarize the recent advances in translational applications in forensic and anthropological science, including paternal biogeographical ancestry inference (PBGAI), surname investigation, and paternal history reconstruction. Whole-Y sequencing or high-resolution panels with high coverage of terminal Y chromosome lineages are essential for capturing the genomic diversity of ethnolinguistically diverse East Asians. Generally, we emphasized the importance of including more ethnolinguistically diverse, underrepresented modern and spatiotemporally different ancient East Asians in human genetic research for a comprehensive understanding of the paternal genetic landscape of East Asians with a detailed time series and for the reconstruction of a reference database in the PBGAI, even including new technology innovations of Telomere-to-Telomere (T2T) for new genetic variation discovery.

Genetic Relationship Among the Kazakh People Based on Y-STR Markers Reveals Evidence of Genetic Variation Among Tribes and Zhuz

Ethnogenesis of Kazakhs took place in Central Asia, a region of high genetic and cultural diversity. Even though archaeological and historical studies have shed some light on the formation of modern Kazakhs, the process of establishment of hierarchical socioeconomic structure in the Steppe remains contentious. In this study, we analyzed haplotype variation at 15 Y-chromosomal short-tandem-repeats obtained from 1171 individuals from 24 tribes representing the three socio-territorial subdivisions (Senior, Middle and Junior zhuz) in Kazakhstan to comprehensively characterize the patrilineal genetic architecture of the Kazakh Steppe. In total, 577 distinct haplotypes were identified belonging to one of 20 haplogroups; 16 predominant haplogroups were confirmed by SNP-genotyping. The haplogroup distribution was skewed towards C2-M217, present in all tribes at a global frequency of 51.9%. Despite signatures of spatial differences in haplotype frequencies, a Mantel test failed to detect a statistically significant correlation between genetic and geographic distance between individuals. An analysis of molecular variance found that ∼8.9% of the genetic variance among individuals was attributable to differences among zhuzes and ∼20% to differences among tribes within zhuzes. The STRUCTURE analysis of the 1164 individuals indicated the presence of 20 ancestral groups and a complex three-subclade organization of the C2-M217 haplogroup in Kazakhs, a result supported by the multidimensional scaling analysis. Additionally, while the majority of the haplotypes and tribes overlapped, a distinct cluster of the O2 haplogroup, mostly of the Naiman tribe, was observed. Thus, firstly, our analysis indicated that the majority of Kazakh tribes share deep heterogeneous patrilineal ancestries, while a smaller fraction of them are descendants of a founder paternal ancestor. Secondly, we observed a high frequency of the C2-M217 haplogroups along the southern border of Kazakhstan, broadly corresponding to both the path of the Mongolian invasion and the ancient Silk Road. Interestingly, we detected three subclades of the C2-M217 haplogroup that broadly exhibits zhuz-specific clustering. Further study of Kazakh haplotypes variation within a Central Asian context is required to untwist this complex process of ethnogenesis.

Dual origins of the Northwest Chinese Kyrgyz: the admixture of Bronze age Siberian and Medieval Niru'un Mongolian Y chromosomes

The Kyrgyz are a trans-border ethnic group, mainly living in Kyrgyzstan. Previous genetic investigations of Central Asian populations have repeatedly investigated the Central Asian Kyrgyz. However, from the standpoint of human evolution and genetic diversity, Northwest Chinese Kyrgyz is one of the more poorly studied populations. In this study, we analyzed the non-recombining portion of the Y-chromosome from 298 male Kyrgyz samples from Xinjiang Uygur Autonomous Region in northwestern China, using a high-resolution analysis of 108 biallelic markers and 17 or 24 STRs. First, via a Y-SNP-based PCA plot, Northwest Chinese Kyrgyz tended to cluster with other Kyrgyz population and are located in the West Asian and Central Asian group. Second, we found that the Northwest Chinese Kyrgyz display a high proportion of Y-lineage R1a1a1b2a2a-Z2125, related to Bronze Age Siberian, and followed by Y-lineage C2b1a3a1-F3796, related to Medieval Niru'un Mongols, such as Uissun tribe from Kazakhs. In these two dominant lineages, two unique recent descent clusters have been detected via NETWORK analysis, respectively, but they have nearly the same TMRCA ages (about 13th-14th centuries). This finding once again shows that the expansions of Mongol Empire had a striking effect on the Central Asian gene pool.

Genetic insights into the paternal admixture history of Chinese Mongolians via high-resolution customized Y-SNP SNaPshot panels

The Mongolian people, one of the Mongolic-speaking populations, are native to the Mongolian Plateau in North China and southern Siberia. Many ancient DNA studies recently reported extensive population transformations during the Paleolithic to historic periods in this region, while little is known about the paternal genetic legacy of modern geographically different Mongolians. Here, we genotyped 215 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) and 37 Y-chromosomal short tandem repeats (Y-STRs) among 679 Mongolian individuals from Hohhot, Hulunbuir, and Ordos in North China using the AGCU Y37 kit and our developed eight Y-SNP SNaPshot panels (including two panels first reported herein). The C-M130 Y-SNP SNaPshot panel defines 28 subhaplogroups, and the N/O/Q complementary Y-SNP SNaPshot panel defines 30 subhaplogroups of N1b-F2930, N1a1a1a1a3-B197, Q-M242, and O2a2b1a1a1a4a-CTS4658, which improved the resolution our developed Y-SNP SNaPshot panel set and could be applied for dissecting the finer-scale paternal lineages of Mongolic speakers. We found a strong association between Mongolian-prevailing haplogroups and some observed microvariants among the newly generated Y-STR haplotype data, suggesting the possibility of haplogroup prediction based on the distribution of Y-STR haplotypes. We identified three main ancestral sources of the observed Mongolian-dominant haplogroups, including the local lineage of C2*-M217 and incoming lineages from other regions of southern East Asia (O2*-M122, O1b*-P31, and N1*-CTS3750) and western Eurasia (R1*-M173). We also observed DE-M145, D1*-M174, C1*-F3393, G*-M201, I-M170, J*-M304, L-M20, O1a*-M119, and Q*-M242 at relatively low frequencies (< 5.00%), suggesting a complex admixture history between Mongolians and other incoming Eurasians from surrounding regions. Genetic clustering analyses indicated that the studied Mongolians showed close genetic affinities with other Altaic-speaking populations and Sinitic-speaking Hui people. The Y-SNP haplotype/haplogroup-based genetic legacy not only revealed that the stratification among geographically/linguistically/ethnically different Chinese populations was highly consistent with the geographical division and language classification, but also demonstrated that patrilineal genetic materials could provide fine-scale genetic structures among geographically different Mongolian people, suggesting that our developed high-resolution Y-SNP SNaPshot panels have the potential for forensic pedigree searches and biogeographical ancestry inference.

Origin of ethnic groups, linguistic families, and civilizations in China viewed from the Y chromosome

East Asia, geographically extending to the Pamir Plateau in the west, to the Himalayan Mountains in the southwest, to Lake Baikal in the north and to the South China Sea in the south, harbors a variety of people, cultures, and languages. To reconstruct the natural history of East Asians is a mission of multiple disciplines, including genetics, archaeology, linguistics, and ethnology. Geneticists confirm the recent African origin of modern East Asians. Anatomically modern humans arose in Africa and immigrated into East Asia via a southern route approximately 50,000 years ago. Following the end of the Last Glacial Maximum approximately 12,000 years ago, rice and millet were domesticated in the south and north of East Asia, respectively, which allowed human populations to expand and linguistic families and ethnic groups to develop. These Neolithic populations produced a strong relation between the present genetic structures and linguistic families. The expansion of the Hongshan people from northeastern China relocated most of the ethnic populations on a large scale approximately 5300 years ago. Most of the ethnic groups migrated to remote regions, producing genetic structure differences between the edge and center of East Asia. In central China, pronounced population admixture occurred and accelerated over time, which subsequently formed the Han Chinese population and eventually the Chinese civilization. Population migration between the north and the south throughout history has left a smooth gradient in north-south changes in genetic structure. Observation of the process of shaping the genetic structure of East Asians may help in understanding the global natural history of modern humans.

Paternal Y chromosomal genotyping reveals multiple large-scale admixtures in the formation of Lolo-Burmese-speaking populations in southwest China

Background: Bai and Yi people are two Tibeto-Burman speaking ethnic groups in Yunnan, southwest China. The genetic structure and history of these two groups are largely unknown due to a lack of available genetic data.Aim: To investigate the paternal genetic structure and population relationship of the Yi and Bai people.Subjects and methods: We collected samples from 278 Bai individuals and 283 Yi individuals from Yunnan and subsequently genotyped 43 phylogenetically relevant Y-SNPs in those samples. We estimated haplogroup frequencies and merged our data with a reference database including 46 representative worldwide populations to infer genetic relationships.Results: Y chromosomal haplogroup O-M175 is the dominant lineage in both Bai and Yi people. The Bai and Yi show a close genetic relationship with other Tibeto-Burman-speaking populations with high frequencies of haplogroup O2a2b1a1-Page23, which is also confirmed by PCA. The frequencies of the Tai-Kadai specific lineage O1a-M119, the southern China widespread lineage O1b-P31 and the eastern China enriched lineage O2a1b-002611, are also relatively high in our studied populations.Conclusions: The paternal Y chromosomal affinity of the Bai and Yi with Tibeto-Burman groups is consistent with the language classification. During the formation of the Bai and Yi populations, there were multiple large-scale admixtures, including the expansion of Neolithic farming populations from northern China, the assimilation of Tai-Kadai-speaking populations in southwest China, the demographic expansion driven by Neolithic agricultural revolution from southern China, and the admixture with populations of military immigration from northern and eastern China.

Genomic Reconstruction of the History of Native Sheep Reveals the Peopling Patterns of Nomads and the Expansion of Early Pastoralism in East Asia

China has a rich resource of native sheep (Ovis aries) breeds associated with historical movements of several nomadic societies. However, the history of sheep and the associated nomadic societies in ancient China remains poorly understood. Here, we studied the genomic diversity of Chinese sheep using genome-wide SNPs, mitochondrial and Y-chromosomal variations in > 1,000 modern samples. Population genomic analyses combined with archeological records and historical ethnic demographics data revealed genetic signatures of the origins, secondary expansions and admixtures, of Chinese sheep thereby revealing the peopling patterns of nomads and the expansion of early pastoralism in East Asia. Originating from the Mongolian Plateau ∼5,000‒5,700 years ago, Chinese sheep were inferred to spread in the upper and middle reaches of the Yellow River ∼3,000‒5,000 years ago following the expansions of the Di-Qiang people. Afterwards, sheep were then inferred to reach the Qinghai-Tibetan and Yunnan-Kweichow plateaus ∼2,000‒2,600 years ago by following the north-to-southwest routes of the Di-Qiang migration. We also unveiled two subsequent waves of migrations of fat-tailed sheep into northern China, which were largely commensurate with the migrations of ancestors of Hui Muslims eastward and Mongols southward during the 12th‒13th centuries. Furthermore, we revealed signs of argali introgression into domestic sheep, extensive historical mixtures among domestic populations and strong artificial selection for tail type and other traits, reflecting various breeding strategies by nomadic societies in ancient China.

Ancient DNA reveals that the genetic structure of the northern Han Chinese was shaped prior to 3,000 years ago

The Han Chinese are the largest ethnic group in the world, and their origins, development, and expansion are complex. Many genetic studies have shown that Han Chinese can be divided into two distinct groups: northern Han Chinese and southern Han Chinese. The genetic history of the southern Han Chinese has been well studied. However, the genetic history of the northern Han Chinese is still obscure. In order to gain insight into the genetic history of the northern Han Chinese, 89 human remains were sampled from the Hengbei site which is located in the Central Plain and dates back to a key transitional period during the rise of the Han Chinese (approximately 3,000 years ago). We used 64 authentic mtDNA data obtained in this study, 27 Y chromosome SNP data profiles from previously studied Hengbei samples, and genetic datasets of the current Chinese populations and two ancient northern Chinese populations to analyze the relationship between the ancient people of Hengbei and present-day northern Han Chinese. We used a wide range of population genetic analyses, including principal component analyses, shared mtDNA haplotype analyses, and geographic mapping of maternal genetic distances. The results show that the ancient people of Hengbei bore a strong genetic resemblance to present-day northern Han Chinese and were genetically distinct from other present-day Chinese populations and two ancient populations. These findings suggest that the genetic structure of northern Han Chinese was already shaped 3,000 years ago in the Central Plain area.

Impact of past climatic changes and resource availability on the population demography of three food-specialist bees

Past climate change is known to have strongly impacted current patterns of genetic variation of animals and plants in Europe. However, ecological factors also have the potential to influence demographic history and thus patterns of genetic variation. In this study, we investigated the impact of past climate, and also the potential impact of host plant species abundance, on intraspecific genetic variation in three codistributed and related specialized solitary bees of the genus Melitta with very similar life history traits and dispersal capacities. We sequenced five independent loci in samples collected from the three species. Our analyses revealed that the species associated with the most abundant host plant species (Melitta leporina) displays unusually high genetic variation, to an extent that is seldom reported in phylogeographic studies of animals and plants. This suggests a potential role of food resource abundance in determining current patterns of genetic variation in specialized herbivorous insects. Patterns of genetic variation in the two other species indicated lower overall levels of diversity, and that M. nigricans could have experienced a recent range expansion. Ecological niche modelling of the three Melitta species and their main host plant species suggested a strong reduction in range size during the last glacial maximum. Comparing observed sequence data with data simulated using spatially explicit models of coalescence suggests that M. leporina recovered a range and population size close to their current levels at the end of the last glaciation, and confirms recent range expansion as the most likely scenario for M. nigricans. Overall, this study illustrates that both demographic history and ecological factors may have contributed to shape current phylogeographic patterns.

Radiocarbon-dated archaeological record of early first millennium B.C. mounted pastoralists in the Kunlun Mountains, China

Pastoral nomadism, as a successful economic and social system drawing on mobile herding, long-distance trade, and cavalry warfare, affected all polities of the Eurasian continent. The role that arid Inner Asia, particularly the areas of northwestern China, Kazakhstan, and Mongolia, played in the emergence of this phenomenon remains a fundamental and still challenging question in prehistoric archaeology of the Eurasian steppes. The cemetery of Liushiu (Xinjiang, China) reveals burial features, bronze bridle bits, weaponry, adornment, horse skulls, and sheep/goat bones, which, together with paleopathological changes in human skeletons, indicate the presence of mobile pastoralists and their flocks at summer pastures in the Kunlun Mountains, ∼2,850 m above sea level. Radiocarbon dates place the onset of the burial activity between 1108 and 893 B.C. (95% probability range) or most likely between 1017 and 926 B.C. (68%). These data from the Kunlun Mountains show a wider frontier within the diversity of mobile pastoral economies of Inner Asia and support the concept of multiregional transitions toward Iron Age complex pastoralism and mounted warfare.

Extended Y chromosome investigation suggests postglacial migrations of modern humans into East Asia via the northern route

Genetic diversity data, from Y chromosome and mitochondrial DNA as well as recent genome-wide autosomal single nucleotide polymorphisms, suggested that mainland Southeast Asia was the major geographic source of East Asian populations. However, these studies also detected Central-South Asia (CSA)- and/or West Eurasia (WE)-related genetic components in East Asia, implying either recent population admixture or ancient migrations via the proposed northern route. To trace the time period and geographic source of these CSA- and WE-related genetic components, we sampled 3,826 males (116 populations from China and 1 population from North Korea) and performed high-resolution genotyping according to the well-resolved Y chromosome phylogeny. Our data, in combination with the published East Asian Y-haplogroup data, show that there are four dominant haplogroups (accounting for 92.87% of the East Asian Y chromosomes), O-M175, D-M174, C-M130 (not including C5-M356), and N-M231, in both southern and northern East Asian populations, which is consistent with the proposed southern route of modern human origin in East Asia. However, there are other haplogroups (6.79% in total) (E-SRY4064, C5-M356, G-M201, H-M69, I-M170, J-P209, L-M20, Q-M242, R-M207, and T-M70) detected primarily in northern East Asian populations and were identified as Central-South Asian and/or West Eurasian origin based on the phylogeographic analysis. In particular, evidence of geographic distribution and Y chromosome short tandem repeat (Y-STR) diversity indicates that haplogroup Q-M242 (the ancestral haplogroup of the native American-specific haplogroup Q1a3a-M3) and R-M207 probably migrated into East Asia via the northern route. The age estimation of Y-STR variation within haplogroups suggests the existence of postglacial (∼18 Ka) migrations via the northern route as well as recent (∼3 Ka) population admixture. We propose that although the Paleolithic migrations via the southern route played a major role in modern human settlement in East Asia, there are ancient contributions, though limited, from WE, which partly explain the genetic divergence between current southern and northern East Asian populations.