ABSTRACT
The identity of the earliest inhabitants of Xinjiang, in the heart of Inner Asia, and the languages that they spoke have long been debated and remain contentious1. Here we present genomic data from 5 individuals dating to around 3000-2800 BC from the Dzungarian Basin and 13 individuals dating to around 2100-1700 BC from the Tarim Basin, representing the earliest yet discovered human remains from North and South Xinjiang, respectively. We find that the Early Bronze Age Dzungarian individuals exhibit a predominantly Afanasievo ancestry with an additional local contribution, and the Early-Middle Bronze Age Tarim individuals contain only a local ancestry. The Tarim individuals from the site of Xiaohe further exhibit strong evidence of milk proteins in their dental calculus, indicating a reliance on dairy pastoralism at the site since its founding. Our results do not support previous hypotheses for the origin of the Tarim mummies, who were argued to be Proto-Tocharian-speaking pastoralists descended from the Afanasievo1,2 or to have originated among the Bactria-Margiana Archaeological Complex3 or Inner Asian Mountain Corridor cultures4. Instead, although Tocharian may have been plausibly introduced to the Dzungarian Basin by Afanasievo migrants during the Early Bronze Age, we find that the earliest Tarim Basin cultures appear to have arisen from a genetically isolated local population that adopted neighbouring pastoralist and agriculturalist practices, which allowed them to settle and thrive along the shifting riverine oases of the Taklamakan Desert.
Subject(s)
Archaeology , Genome, Human/genetics , Genomics , Human Migration/history , Mummies/history , Phylogeny , Agriculture/history , Animals , Cattle , China , Cultural Characteristics , Dental Calculus/chemistry , Desert Climate , Diet/history , Europe , Female , Goats , Grassland , History, Ancient , Humans , Male , Milk Proteins/analysis , Phylogeography , Principal Component Analysis , Proteome/analysis , Proteomics , Sheep , Whole Genome SequencingABSTRACT
The origin and early dispersal of speakers of Transeurasian languages-that is, Japanese, Korean, Tungusic, Mongolic and Turkic-is among the most disputed issues of Eurasian population history1-3. A key problem is the relationship between linguistic dispersals, agricultural expansions and population movements4,5. Here we address this question by 'triangulating' genetics, archaeology and linguistics in a unified perspective. We report wide-ranging datasets from these disciplines, including a comprehensive Transeurasian agropastoral and basic vocabulary; an archaeological database of 255 Neolithic-Bronze Age sites from Northeast Asia; and a collection of ancient genomes from Korea, the Ryukyu islands and early cereal farmers in Japan, complementing previously published genomes from East Asia. Challenging the traditional 'pastoralist hypothesis'6-8, we show that the common ancestry and primary dispersals of Transeurasian languages can be traced back to the first farmers moving across Northeast Asia from the Early Neolithic onwards, but that this shared heritage has been masked by extensive cultural interaction since the Bronze Age. As well as marking considerable progress in the three individual disciplines, by combining their converging evidence we show that the early spread of Transeurasian speakers was driven by agriculture.
Subject(s)
Agriculture/history , Archaeology , Genetics, Population , Human Migration/history , Language/history , Linguistics , China , Datasets as Topic , Geographic Mapping , History, Ancient , Humans , Japan , Korea , MongoliaABSTRACT
The application of Zooarchaeology by Mass Spectrometry (ZooMS) on Pleistocene sites in Europe and northern Asia has resulted in the discovery of important new hominin fossils and has expanded the range of identified fauna. However, no systematic, large-scale application of ZooMS on Palaeolithic sites in East Asia has been attempted thus far. Here, we analyse 866 morphologically non-diagnostic bones from Jinsitai Cave in northeast China and Yumidong Cave in South China, from archaeological horizons dating to 150-10 ka BP. Bones from both sites revealed a high degree of collagen preservation and potentially time-related deamidation patterns, despite being located in very distinct environmental settings. At Jinsitai, we identified 31 camel bones, five of which were radiocarbon dated to 37-20 ka BP. All dated specimens correspond to colder periods of Marine Isotope Stages 3 and 2. We regard the presence of camels at Jinsitai as evidence of wild camels being a megafauna taxon targeted, most likely by early modern humans, during their expansion across northeast Asia. This large-scale application of ZooMS in China highlights the potential of the method for furthering our knowledge of the palaeoanthropological and zooarchaeological records of East Asia.
Subject(s)
Camelus , Hominidae , Humans , Animals , Mass Spectrometry/methods , Fossils , China , Archaeology/methods , Radiometric DatingABSTRACT
Salmonella enterica (S. enterica) has infected humans for a long time, but its evolutionary history and geographic spread across Eurasia is still poorly understood. Here, we screened for pathogen DNA in 14 ancient individuals from the Bronze Age Quanergou cemetery (XBQ), Xinjiang, China. In 6 individuals we detected S. enterica. We reconstructed S. enterica genomes from those individuals, which form a previously undetected phylogenetic branch basal to Paratyphi C, Typhisuis and Choleraesuis-the so-called Para C lineage. Based on pseudogene frequency, our analysis suggests that the ancient S. enterica strains were not host adapted. One genome, however, harbors the Salmonella pathogenicity island 7 (SPI-7), which is thought to be involved in (para)typhoid disease in humans. This offers first evidence that SPI-7 was acquired prior to the emergence of human-adapted Paratyphi C around 1,000 years ago. Altogether, our results show that Salmonella enterica infected humans in Eastern Eurasia at least 3,000 years ago, and provide the first ancient DNA evidence for the spread of a pathogen along the Proto-Silk Road.
Subject(s)
Salmonella Infections/genetics , Salmonella Infections/history , Salmonella Infections/transmission , Salmonella enterica/genetics , China , DNA, Ancient , Evolution, Molecular , History, Ancient , Humans , Phylogeny , Virulence Factors/geneticsABSTRACT
Bones are one of the most common biological types of evidence in forensic cases. Discriminating human bones from irrelevant species is important for the identification of victims; however, the highly degraded bones could be undiagnostic morphologically and difficult to analyze with standard DNA profiling approaches. The same challenge also exists in archaeological studies. Here, we present an initial study of an analytical strategy that involves zooarchaeology by mass spectrometry (ZooMS) and ancient DNA methods. Through the combined strategy, we managed to identify the only biological evidence of a two-decades-old murder case - a small piece of human bone out of 19 bone fragments - and confirmed the kinship between the victim and the putative parents through joint application of next-generation sequencing (NGS) and Sanger sequencing methods. ZooMS effectively screened out the target human bone while ancient DNA methods improve the DNA yields. The combined strategy in this case outperforms the standard DNA profiling approach with shorter time, less cost, as well as higher reliability for the genetic identification results. HIGHLIGHTS: ⢠The first application of zooarchaeology by mass spectrometry technique in the forensic case for screening out human bones from bone fragment mixtures. ⢠Application of ancient DNA technique to recover the highly degraded DNA sequence from the challenging sample that failed standard DNA profiling approaches. ⢠A fast, sensitive, and low-cost strategy that combines the strengths of protein analysis and DNA analysis for kinship identification in forensic research.
Subject(s)
DNA, Ancient , DNA , Humans , Reproducibility of Results , Mass Spectrometry , Bone and Bones , DNA Fingerprinting/methodsABSTRACT
OBJECTIVES: Subbranches of Y-chromosome haplogroup C2a-L1373 are founding paternal lineages in northern Asia and Native American populations. Our objective was to investigate C2a-L1373 differentiation in northern Asia and its implications for Native American origins. MATERIALS AND METHODS: Sequences of rare subbranches (n = 43) and ancient individuals (n = 37) of C2a-L1373 (including P39 and MPB373), were used to construct phylogenetic trees with age estimation by BEAST software. RESULTS: C2a-L1373 expanded rapidly approximately 17.7,000-14.3,000 years ago (kya) after the last glacial maximum (LGM), generating numerous sublineages which became founding paternal lineages of modern northern Asian and Native American populations (C2a-P39 and C2a-MPB373). The divergence pattern supports possible initiation of differentiation in low latitude regions of northern Asia and northward diffusion after the LGM. There is a substantial gap between the divergence times of C2a-MPB373 (approximately 22.4 or 17.7 kya) and C2a-P39 (approximately 14.3 kya), indicating two possible migration waves. DISCUSSION: We discussed the decreasing time interval of "Beringian standstill" (2.5 ky or smaller) and its reduced significance. We also discussed the multiple possibilities for the peopling of the Americas: the "Long-term Beringian standstill model," the "Short-term Beringian standstill model," and the "Multiple waves of migration model." Our results support the argument from ancient DNA analyses that the direct ancestor group of Native Americans is an admixture of "Ancient Northern Siberians" and Paleolithic communities from the Amur region, which appeared during the post-LGM era, rather than ancient populations in greater Beringia, or an adjacent region, before the LGM.
Subject(s)
American Indian or Alaska Native , Asian People , Chromosomes, Human, Y/genetics , Human Migration/history , Anthropology, Physical , Asia, Northern , Asian People/classification , Asian People/genetics , Asian People/history , History, Ancient , Humans , Male , North America , Phylogeny , American Indian or Alaska Native/classification , American Indian or Alaska Native/genetics , American Indian or Alaska Native/historyABSTRACT
Hexaploid common wheat is one of the most important food crops worldwide. Common wheat domestication began in the Fertile Crescent of the Near East approximately 10 000 years ago and then spread west into Europe and eastward into East Asia and China. However, the possible spreading route into and within China is still unclear. In this study, we successfully extracted DNA from single ancient wheat seeds and sequenced the whole genome of seven ancient samples from Xiaohe and Gumugou cemeteries in Xinjiang, China. Genomic inference and morphological observation confirmed their identity as hexaploid common wheat grown in prehistoric China at least 3200 years before present (BP). Phylogenetic and admixture analyses with RNA-seq data of modern hexaploid wheat cultivars from both China and Western countries demonstrated a close kinship of the ancient wheat to extant common wheat landraces in southwestern China. The highly similar allelic frequencies in modern landraces of the Qinghai-Tibetan plateau with the ancient wheat support the previously suggested southwestern spreading route into highland China. A subsequent dispersal route from the Qinghai-Tibetan plateau margins to the Yangtze valley was proposed in this study. Furthermore, the common wheat populations grown in the Middle and Lower Yangtze valley wheat zones were also proposed to be established by population admixture with the wheat grown in the Upper Yangtze valley. Our study reports ancient common wheat sequences at a genome-wide scale, providing important information on the origin, dispersal, and genetic improvement under cultivation of present-day wheat landraces grown in China.
Subject(s)
Genome, Plant , Triticum/genetics , China , DNA, Plant/chemistry , Gene Frequency , Phylogeny , Seed Dispersal , Seeds/anatomy & histology , Seeds/genetics , Sequence Analysis, RNA , Triticum/anatomy & histologyABSTRACT
Functional E-cadherin loss, a hallmark of epithelial-mesenchymal transition (EMT), is important for metastasis. However, the mechanism of Snail2 in hepatocellular carcinoma (HCC) EMT and metastasis remains unclear. Here, we showed that Snail2 was upregulated in primary HCC, and significantly increased during transforming growth factor-ß-induced liver cell EMT. Snail2-overexpressing and knockdown cell lines have been established to determine its function in EMT in HCC. H3K9 methylation was upregulated and H3K4 and H3K56 acetylation were downregulated at the E-cadherin promoter in Snail2-overexpressing cancer cells. Furthermore, Snail2 interacted with G9a and histone deacetylases (HDACs) to form a complex to suppress E-cadherin transcription. Snail2 overexpression enhanced migration and invasion in HCC cells, whereas G9a and HDAC inhibition significantly reversed this effect. Moreover, Snail2 overexpression in cancer cells increased tumor metastasis and shortened survival time in mice, whereas G9a and HDAC inhibitors extended survival. Our study not only reveals a critical mechanism underlying the epigenetic regulation of EMT but also suggests novel treatment strategies for HCC.
Subject(s)
Cadherins/metabolism , Carcinoma, Hepatocellular/metabolism , Epigenesis, Genetic , Epithelial-Mesenchymal Transition/genetics , Histocompatibility Antigens/metabolism , Histone Deacetylases/metabolism , Histone-Lysine N-Methyltransferase/metabolism , Liver Neoplasms/metabolism , Snail Family Transcription Factors/metabolism , Acetylation , Animals , Azepines/therapeutic use , Carcinoma, Hepatocellular/secondary , Cell Movement , Disease Progression , Down-Regulation , Female , Histone Deacetylase Inhibitors/therapeutic use , Humans , Hydroxamic Acids/therapeutic use , Liver/drug effects , Liver/metabolism , Liver Neoplasms/pathology , Methylation , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Neoplasm Metastasis , Quinazolines/therapeutic use , Transcription, Genetic , Transforming Growth Factor beta/pharmacologyABSTRACT
Ancient DNA studies have always refreshed our understanding of the human past that cannot be tracked by modern DNA alone. Until recently, ancient mitochondrial genomic studies in East Asia were still very limited. Here, we retrieved the whole mitochondrial genome of an 8,400-year-old individual from Inner Mongolia, China. Phylogenetic analyses show that the individual belongs to a previously undescribed clade under haplogroup C5d that most probably originated in northern Asia and may have a very low frequency in extant populations that have not yet been sampled. We further characterized the demographic history of mitochondrial haplogroups C5 and C5d and found that C5 experienced a sharp increase in population size starting around 4,000 years before present, the time when intensive millet farming was developed by populations who are associated with the Lower Xiajiadian culture and was widely adopted in northern China. We caution that people related to haplogroup C5 may have added this farming technology to their original way of life and that the various forms of subsistence may have provided abundant food sources and further contributed to the increase in population size.
Subject(s)
Genome, Mitochondrial/genetics , Haplotypes/genetics , DNA, Ancient , DNA, Mitochondrial , Genotyping Techniques , History, Ancient , Humans , Mongolia/epidemiology , PhylogenyABSTRACT
The complete mitochondrial genome of one 700-year-old individual found in Tashkurgan, Xinjiang was target enriched and sequenced in order to shed light on the population history of Tashkurgan and determine the phylogenetic relationship of haplogroup U5a. The ancient sample was assigned to a subclade of haplogroup U5a2a1, which is defined by two rare and stable transversions at 16114A and 13928C. Phylogenetic analysis shows a distribution pattern for U5a2a that is indicative of an origin in the Volga-Ural region and exhibits a clear eastward geographical expansion that correlates with the pastoral culture also entering the Eurasian steppe. The haplogroup U5a2a present in the ancient Tashkurgan individual reveals prehistoric migration in the East Pamir by pastoralists. This study shows that studying an ancient mitochondrial genome is a useful approach for studying the evolutionary process and population history of Eastern Pamir.
Subject(s)
Genome, Mitochondrial , Human Migration/history , China , DNA, Ancient/chemistry , History, Medieval , Humans , Phylogeny , Sequence Analysis, DNAABSTRACT
BACKGROUND: Accumulated evidence suggests that dysregulated expression of long non-coding RNAs (lncRNAs) may play a critical role in tumorigenesis and prognosis of cancer, indicating the potential utility of lncRNAs as cancer prognostic or diagnostic markers. However, the power of lncRNA signatures in predicting the survival of patients with non-small cell lung cancer (NSCLC) has not yet been investigated. METHODS: We performed an array-based transcriptional analysis of lncRNAs in large patient cohorts with NSCLC by repurposing microarray probes from the gene expression omnibus database. A risk score model was constructed based on the expression data of these eight lncRNAs in the training dataset of NSCLC patients and was subsequently validated in other two independent NSCLC datasets. The biological implications of prognostic lncRNAs were also analyzed using the functional enrichment analysis. RESULTS: An expression pattern of eight lncRNAs was found to be significantly associated with overall survival (OS) of NSCLC patients in the training dataset. With the eight-lncRNA signature, patients of the training dataset could be classified into high- and low-risk groups with significantly different OS (median survival 1.67 vs. 6.06 years, log-rank test p = 4.33E-09). The prognostic power of eight-lncRNA signature was further validated in other two non-overlapping independent NSCLC cohorts, demonstrating good reproducibility and robustness of this eight-lncRNA signature in predicting OS of NSCLC patients. Multivariate regression and stratified analysis suggested that the prognostic power of the eight-lncRNA signature was independent of clinical and pathological factors. Functional enrichment analyses revealed potential functional roles of the eight prognostic lncRNAs in tumorigenesis. CONCLUSIONS: These findings indicate that the eight-lncRNA signature may be an effective independent prognostic molecular biomarker in the prediction of NSCLC patient survival.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Gene Expression Profiling , Lung Neoplasms/genetics , RNA, Long Noncoding/genetics , Aged , Cohort Studies , Databases, Genetic , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Middle Aged , Multivariate Analysis , Open Reading Frames/genetics , Prognosis , Proportional Hazards Models , ROC Curve , Reproducibility of Results , Risk Factors , Survival AnalysisABSTRACT
Humans first arrived on Madagascar only a few thousand years ago. Subsequent habitat destruction and hunting activities have had significant impacts on the island's biodiversity, including the extinction of megafauna. For example, we know of 17 recently extinct 'subfossil' lemur species, all of which were substantially larger (body mass â¼11-160 kg) than any living population of the â¼100 extant lemur species (largest body mass â¼6.8 kg). We used ancient DNA and genomic methods to study subfossil lemur extinction biology and update our understanding of extant lemur conservation risk factors by i) reconstructing a comprehensive phylogeny of extinct and extant lemurs, and ii) testing whether low genetic diversity is associated with body size and extinction risk. We recovered complete or near-complete mitochondrial genomes from five subfossil lemur taxa, and generated sequence data from population samples of two extinct and eight extant lemur species. Phylogenetic comparisons resolved prior taxonomic uncertainties and confirmed that the extinct subfossil species did not comprise a single clade. Genetic diversity estimates for the two sampled extinct species were relatively low, suggesting small historical population sizes. Low genetic diversity and small population sizes are both risk factors that would have rendered giant lemurs especially susceptible to extinction. Surprisingly, among the extant lemurs, we did not observe a relationship between body size and genetic diversity. The decoupling of these variables suggests that risk factors other than body size may have as much or more meaning for establishing future lemur conservation priorities.
Subject(s)
Body Size , Extinction, Biological , Genomics/methods , Lemur , Paleontology/methods , Animals , Body Size/genetics , Body Size/physiology , DNA/analysis , DNA/genetics , Fossils , Lemur/classification , Lemur/genetics , Lemur/physiology , Madagascar , PhylogenyABSTRACT
To gain insight into the social organization of a population associated with the Dawenkou period, we performed ancient DNA analysis of 18 individuals from human remains from the Fujia site in Shandong Province, China. Directly radiocarbon dated to 4800-4500 cal BP, the Fujia site is assumed to be associated with a transitional phase from matrilineal clans to patrilineal monogamous families. Our results reveal a low mitochondrial DNA diversity from the site and population. Combined with Y chromosome data, the pattern observed at the Fujia site is most consistent with a matrilineal community. The patterns also suggest that the bond of marriage was de-emphasized compared with the bonds of descent at Fujia.
Subject(s)
DNA, Mitochondrial/analysis , Genetic Variation , Social Dominance/history , China/ethnology , DNA, Mitochondrial/history , Female , History, Ancient , Humans , Male , Marriage/ethnology , Marriage/history , Sequence Analysis, DNAABSTRACT
Xinjiang is at the crossroads between East and West Eurasia, and it harbors a relatively complex genetic history. In order to better understand the population movements and interactions in this region, mitochondrial and Y chromosome analyses on 40 ancient human remains from the Tianshanbeilu site in eastern Xinjiang were performed. Twenty-nine samples were successfully assigned to specific mtDNA haplogroups, including the west Eurasian maternal lineages of U and W and the east Eurasian maternal lineages of A, C, D, F, G, Z, M7, and M10. In the male samples, two Y chromosome haplogroups, C* and N1 (xN1a, N1c), were successfully assigned. Our mitochondrial and Y-chromosomal DNA analyses combined with the archaeological studies revealed that the Di-qiang populations from the Hexi Corridor had migrated to eastern Xinjiang and admixed with the Eurasian steppe populations in the early Bronze Age.
Subject(s)
Asian People/genetics , Chromosomes, Human, Y/genetics , DNA, Mitochondrial/genetics , Human Migration , Anthropology, Physical , China , Female , Humans , Male , Microsatellite Repeats/genetics , Polymorphism, Single Nucleotide/geneticsABSTRACT
Hepatitis B virus is a globally distributed pathogen and the history of HBV infection in humans predates 10000 years. However, long-term evolutionary history of HBV in Eastern Eurasia remains elusive. We present 34 ancient HBV genomes dating between approximately 5000 to 400 years ago sourced from 17 sites across Eastern Eurasia. Ten sequences have full coverage, and only two sequences have less than 50% coverage. Our results suggest a potential origin of genotypes B and D in Eastern Asia. We observed a higher level of HBV diversity within Eastern Eurasia compared to Western Eurasia between 5000 and 3000 years ago, characterized by the presence of five different genotypes (A, B, C, D, WENBA), underscoring the significance of human migrations and interactions in the spread of HBV. Our results suggest the possibility of a transition from non-recombinant subgenotypes (B1, B5) to recombinant subgenotypes (B2 - B4). This suggests a shift in epidemiological dynamics within Eastern Eurasia over time. Here, our study elucidates the regional origins of prevalent genotypes and shifts in viral subgenotypes over centuries.
Subject(s)
Hepatitis B virus , Human Migration , Humans , Hepatitis B virus/genetics , Phylogeny , Genotype , Biological Evolution , DNA, Viral/geneticsABSTRACT
BACKGROUND: The West Liao River valley in Northeast China is an ecologically diverse region, populated in prehistory by human populations with a wide range of cultures and modes of subsistence. To help understand the human evolutionary history of this region, we performed Y chromosome analyses on ancient human remains from archaeological sites ranging in age from 6500 to 2700 BP. RESULTS: 47 of the 70 individuals provided reproducible results. They were assigned into five different Y sub-haplogroups using diagnostic single nucleotide polymorphisms, namely N1 (xN1a, N1c), N1c, C/C3e, O3a (O3a3) and O3a3c. We also used 17 Y short tandem repeat loci in the non-recombining portion of the Y chromosome. There appears to be significant genetic differences between populations of the West Liao River valley and adjacent cultural complexes in the prehistoric period, and these prehistoric populations were shown to carry similar haplotypes as present-day Northeast Asians, but at markedly different frequencies. CONCLUSION: Our results suggest that the prehistoric cultural transitions were associated with immigration from the Yellow River valley and the northern steppe into the West Liao River valley. They reveal the temporal continuity of Y chromosome lineages in populations of the West Liao River valley over 5000 years, with a concurrent increase in lineage diversity caused by an influx of immigrants from other populations.
Subject(s)
Chromosomes, Human, Y , Hominidae/genetics , Animals , China , Emigration and Immigration , Genetic Variation , Genetics, Population , Haplotypes , Humans , Male , Microsatellite Repeats , Polymorphism, Single Nucleotide , RiversABSTRACT
Multidisciplinary research on human remains can provide important information about population dynamics, culture diffusion, as well as social organization and customs in history. In this study, multidisciplinary analyses were undertaken on a joint burial (M56) in the Shuangzhao cemetery of the Tang Dynasty (618-907 AD), one of the most prosperous dynasties in Chinese history, to shed light on the genetic profile and sociocultural aspects of this dynasty. The archaeological investigation suggested that this burial belonged to the Mid-Tang period and was used by common civilians. The osteological analysis identified the sex, age, and health status of the three individuals excavated from M56, who shared a similar diet inferred from the stable isotopic data. Genomic evidence revealed that these co-buried individuals had no genetic kinship but all belonged to the gene pool of the ancient populations in the Central Plains, represented by Yangshao and Longshan individuals, etc. Multiple lines of evidence, including archaeology, historic records, as well as chemical and genetic analyses, have indicated a very probable familial joint burial of husband and wives. Our study provides insights into the burial customs and social organization of the Tang Dynasty and reconstructs a scenario of civilian life in historic China.
Subject(s)
Burial , Cemeteries , Humans , History, Medieval , Burial/history , Cemeteries/history , Isotopes , Culture , ArchaeologyABSTRACT
Teaching quality is directly related to the performance of universities in fostering talents. Being innovative, high-level, and challenging (IHC) is the basic goal of course reform at universities in the new era. It is essential to reform the contents and teaching mode to improve the IHC properties of the existing courses. We first designed the three-dimensional goals of Molecular Biology Experiment teaching and the contents to support these goals. Then, we pinpointed the common points shared by blended teaching and experiment course, and designed the ways of blended teaching for the course. The reformed course contents and teaching mode have enhanced its IHC properties, and achieved good teaching performance. This paper provides a reference for the reform of experiment courses in universities.
Subject(s)
Molecular Biology , Students , Humans , UniversitiesABSTRACT
In order to study the genetic characteristics of the Lower Xiajiadian culture (LXC) population, a main bronze culture branch in northern China dated 4500-3500 years ago, two uniparentally inherited markers, mitochondrial DNA and Y-chromosome single-nucleotide polymorphisms (Y-SNPs), were analyzed on 14 human remains excavated from the Dadianzi site. The 14 sequences, which contained 13 haplotypes, were assigned to 9 haplogroups, and Y-SNP typing of 5 male individuals assigned them to haplogroups N (M231) and O3 (M122). The results indicate that the LXC population mainly included people carrying haplogroups from northern Asia who had lived in this region since the Neolithic period, as well as genetic evidence of immigration from the Central Plain. Later in the Bronze Age, part of the population migrated to the south away from a cooler climate, which ultimately influenced the gene pool in the Central Plain. Thus, climate change is an important factor, which drove the population migration during the Bronze Age in northern China. Based on these results, the local genetic continuity did not seem to be affected by outward migration, although more data are needed especially from other ancient populations to determine the influence of return migration on genetic continuity.
Subject(s)
Asian People/genetics , Emigration and Immigration/history , Asian People/history , China , Chromosomes, Human, Y , DNA/chemistry , DNA, Mitochondrial/chemistry , Female , Geography , History, Ancient , Humans , Male , Polymorphism, Single Nucleotide , Population/genetics , Sequence Analysis, DNAABSTRACT
BACKGROUND: The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA) derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far. RESULTS: Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C) and the West Eurasian haplogroups (H and K), whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals. CONCLUSION: Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin.