ABSTRACT
Jujube (Ziziphus jujuba) exhibits a rich diversity in fruit shape, with natural occurrences of gourd-like, flattened, and other special shapes. Despite the ongoing research into fruit shape, studies integrating elliptical Fourier descriptors (EFDs) with both Short Time-series Expression Miner (STEM) and weighted gene co-expression network analysis (WGCNA) for gene discovery remain scarce. In this study, six cultivars of jujube fruits with distinct shapes were selected, and samples were collected from the fruit set period to the white mature stage across five time points for shape analysis and transcriptome studies. By combining EFDs with WGCNA and STEM, the study aimed to identify the critical periods and key genes involved in the formation of jujube fruit shape. The findings indicated that the D25 (25 days after flowering) is crucial for the development of jujube fruit shape. Moreover, ZjAGL80, ZjABI3, and eight other genes have been implicated to regulate the shape development of jujubes at different periods of fruit development, through seed development and fruit development pathway. In this research, EFDs were employed to precisely delineate the shape of jujube fruits. This approach, in conjunction with transcriptome, enhanced the precision of gene identification, and offered an innovative methodology for fruit shape analysis. This integration facilitates the advancement of research into the morphological characteristics of plant fruits, underpinning the development of a refined framework for the genetic underpinnings of fruit shape variation.
ABSTRACT
Detailed knowledge on tissue-specific metabolic reprogramming in diabetic nephropathy (DN) is vital for more accurate understanding the molecular pathological signature and developing novel therapeutic strategies. In the present study, a spatial-resolved metabolomics approach based on air flow-assisted desorption electrospray ionization (AFADESI) and matrix-assisted laser desorption ionization (MALDI) integrated mass spectrometry imaging (MSI) was proposed to investigate tissue-specific metabolic alterations in the kidneys of high-fat diet-fed and streptozotocin (STZ)-treated DN rats and the therapeutic effect of astragaloside IV, a potential anti-diabetic drug, against DN. As a result, a wide range of functional metabolites including sugars, amino acids, nucleotides and their derivatives, fatty acids, phospholipids, sphingolipids, glycerides, carnitine and its derivatives, vitamins, peptides, and metal ions associated with DN were identified and their unique distribution patterns in the rat kidney were visualized with high chemical specificity and high spatial resolution. These region-specific metabolic disturbances were ameliorated by repeated oral administration of astragaloside IV (100 mg/kg) for 12 weeks. This study provided more comprehensive and detailed information about the tissue-specific metabolic reprogramming and molecular pathological signature in the kidney of diabetic rats. These findings highlighted the promising potential of AFADESI and MALDI integrated MSI based metabolomics approach for application in metabolic kidney diseases.
ABSTRACT
Protein-truncating variants (PTVs) have important impacts on phenotype diversity and disease. However, their population genetics characteristics in more globally diverse populations are not well defined. Here, we describe patterns of PTVs in 1320 genes sequenced in 10,539 healthy controls and 9434 patients with psoriasis, all of Han Chinese ancestry. We identify 8720 PTVs, of which 77% are novel, and estimate 88% of all PTVs are deleterious and subject to purifying selection. Furthermore, we show that individuals with psoriasis have a significantly higher burden of PTVs compared to controls (P = 0.02). Finally, we identified 18 PTVs in 14 genes with unusually high levels of population differentiation, consistent with the action of local adaptation. Our study provides insights into patterns and consequences of PTVs.
ABSTRACT
Spatially resolved metabolic profiling of brain is vital for elucidating tissue-specific molecular histology and pathology underlying diabetic encephalopathy (DE). In this study, a spatially resolved metabolomic method based on air-flow-assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI) was developed for investigating the region-specific metabolic disturbances in the brain of DE model rats induced by a high-fat diet in combination with streptozotocin administration. A total of 19 discriminating metabolites associated with glycolysis and the pentose phosphate pathway (PPP); the glutamate/gamma aminobutyric acid-glutamine cycle and tricarboxylic acid cycle; nucleotide metabolism; lipid metabolism; carnitine homeostasis; and taurine, ascorbic acid, histidine, and choline metabolism were identified and located in the brains of the diabetic rats simultaneously for the first time. The results indicated that increased glycolytic and PPP activity; dysfunction of mitochondrial metabolism; dysregulation of adenosinergic, glutamatergic, dopaminergic, cholinergic, and histaminergic systems; disorder of osmotic regulation and antioxidant system; and disorder of lipid metabolism occur in a region-specific fashion in the brains of DE rats. Thus, this study provides valuable information regarding the molecular pathological signature of DE. These findings also underline the high potential of AFADESI-MSI for applications in various central nervous system diseases.
Subject(s)
Brain Diseases , Diabetes Mellitus, Experimental , Animals , Metabolomics , Rats , Spectrometry, Mass, Electrospray Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , StreptozocinABSTRACT
Understanding of the nephrotoxicity induced by drug candidates is vital to drug discovery and development. Herein, an in situ metabolomics method based on air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) was established for direct analysis of metabolites in renal tissue sections. This method was subsequently applied to investigate spatially resolved metabolic profile changes in rat kidney after the administration of aristolochic acid I, a known nephrotoxic drug, aimed to discover metabolites associated with nephrotoxicity. As a result, 38 metabolites related to the arginine-creatinine metabolic pathway, the urea cycle, the serine synthesis pathway, metabolism of lipids, choline, histamine, lysine, and adenosine triphosphate were significantly changed in the group treated with aristolochic acid I. These metabolites exhibited a unique distribution in rat kidney and a good spatial match with histopathological renal lesions. This study provides new insights into the mechanisms underlying aristolochic acids nephrotoxicity and demonstrates that AFADESI-MSI-based in situ metabolomics is a promising technique for investigation of the molecular mechanism of drug toxicity.
ABSTRACT
BACKGROUND: A vascular tumor is a benign tumor with unique clinical and pathological features. Perirenal vascular tumor is extremely rare and has not yet been reported. Clinically, it manifests as soreness and swelling. Color ultrasound and renal angiography illustrated the perirenal mass, which was closely connected with the kidney and the surrounding tissues and organs. Histology showed extensive embedded perirenal fat, and thin-walled vascular tissue displayed a pink stain due to red blood cells. CASE SUMMARY: Herein, a case of robot-assisted retroperitoneal laparoscopic excision of a perirenal vascular tumor is reported. Analysis of the clinical, biological, and histological features of the perirenal vascular tumor can provide an in-depth understanding of the disease, which provides a theoretical and practical basis for better diagnosis and treatment. CONCLUSION: This study contributes to a practical basis for the diagnosis and treatment of perirenal hemangiom.
ABSTRACT
Admixture has played a prominent role in shaping patterns of human genomic variation, including gene flow with now-extinct hominins like Neanderthals and Denisovans. Here, we describe a novel probabilistic method called IBDmix to identify introgressed hominin sequences, which, unlike existing approaches, does not use a modern reference population. We applied IBDmix to 2,504 individuals from geographically diverse populations to identify and analyze Neanderthal sequences segregating in modern humans. Strikingly, we find that African individuals carry a stronger signal of Neanderthal ancestry than previously thought. We show that this can be explained by genuine Neanderthal ancestry due to migrations back to Africa, predominately from ancestral Europeans, and gene flow into Neanderthals from an early dispersing group of humans out of Africa. Our results refine our understanding of Neanderthal ancestry in African and non-African populations and demonstrate that remnants of Neanderthal genomes survive in every modern human population studied to date.
Subject(s)
Black People/genetics , Evolution, Molecular , Neanderthals/genetics , Animals , Gene Flow , Human Migration , Humans , Models, Genetic , Pedigree , Polymorphism, GeneticABSTRACT
This study identified 35 new sites for targeted transgene insertion that have the potential to serve as new human genomic "safe harbor" sites (SHS). SHS potential for these 35 sites, located on 16 chromosomes, including both arms of the human X chromosome, and for the existing human SHS AAVS1, hROSA26, and CCR5 was assessed using eight different desirable, widely accepted criteria for SHS verifiable with human genomic data. Three representative newly identified sites on human chromosomes 2 and 4 were then experimentally validated by in vitro and in vivo cleavage-sensitivity tests, and analyzed for population-level and cell line-specific sequence variants that might confound site targeting. The highly ranked site on chromosome 4 (SHS231) was further characterized by targeted homology-dependent and -independent transgene insertion and expression in different human cell lines. The structure and fidelity of transgene insertions at this site were confirmed, together with analyses that demonstrated stable expression and function of transgene-encoded proteins, including fluorescent protein markers, selectable marker cassettes, and Cas9 protein variants. SHS-integrated transgene-encoded Cas9 proteins were shown to be capable of introducing a large (17 kb) gRNA-specified deletion in the PAX3/FOXO1 fusion oncogene in human rhabdomyosarcoma cells and as a Cas9-VPR fusion protein to upregulate expression of the muscle-specific transcription factor MYF5 in human rhabdomyosarcoma cells. An engineering "toolkit" was developed to enable easy use of the most extensively characterized of these new human sites, SHS231, located on the proximal long arm of chromosome 4. The target sites identified here have the potential to serve as additional human SHS to enable basic and clinical gene editing and genome-engineering applications.
Subject(s)
Chromosomes, Human , Mutagenesis, Insertional , Transgenes , Base Sequence , CRISPR-Cas Systems , Cell Line , Chromosome Breakpoints , Gene Editing , Gene Expression , Gene Knock-In Techniques , Gene Targeting , Genetic Loci , Genome, Human , Geographic Mapping , HumansABSTRACT
Flores Island, Indonesia, was inhabited by the small-bodied hominin species Homo floresiensis, which has an unknown evolutionary relationship to modern humans. This island is also home to an extant human pygmy population. Here we describe genome-scale single-nucleotide polymorphism data and whole-genome sequences from a contemporary human pygmy population living on Flores near the cave where H. floresiensis was found. The genomes of Flores pygmies reveal a complex history of admixture with Denisovans and Neanderthals but no evidence for gene flow with other archaic hominins. Modern individuals bear the signatures of recent positive selection encompassing the FADS (fatty acid desaturase) gene cluster, likely related to diet, and polygenic selection acting on standing variation that contributed to their short-stature phenotype. Thus, multiple independent instances of hominin insular dwarfism occurred on Flores.
Subject(s)
Adaptation, Biological/genetics , Biological Evolution , Body Height/genetics , Dwarfism/genetics , Islands , Population/genetics , Selection, Genetic , Animals , Gene Flow , Genome, Human , Humans , Indonesia , Neanderthals/geneticsABSTRACT
This study aimed to investigate the neurophysiological characteristics of young people with depressive personality disorder using event-related potentials (ERP). To explore the effects of visual-emotional words on ERP, mainly N350, we recruited 19 individuals with a depressive personality disorder and 10 healthy controls. ERP were recorded while the subjects took decisions on target words that were classified into three categories: emotionally positive, negative, and neutral. The ERP signals were then separately averaged according to the subjects' classifications. Data analysis showed that the amplitude of N350 was larger in response to positive and negative words than to neutral words. The latency of N350 was longer in negative words, in contrast with positive and neutral words. However, no difference was found between the two groups. These results suggest that neurophysiological characteristics of young people with a depressive personality disorder in visual-emotional word processing have not yet been influenced by their personality traits. To some extent, N350 reflected semantic processes and was not sensitive to participants' mood state.
ABSTRACT
Heritable loss of function mutations in the human RECQ helicase genes BLM, WRN, and RECQL4 cause Bloom, Werner, and Rothmund-Thomson syndromes, cancer predispositions with additional developmental or progeroid features. In order to better understand RECQ pathogenic and population variation, we systematically analyzed genetic variation in all five human RECQ helicase genes. A total of 3,741 unique base pair-level variants were identified, across 17,605 potential mutation sites. Direct counting of BLM, RECQL4, and WRN pathogenic variants was used to determine aggregate and disease-specific carrier frequencies. The use of biochemical and model organism data, together with computational prediction, identified over 300 potentially pathogenic population variants in RECQL and RECQL5, the two RECQ helicases that are not yet linked to a heritable deficiency syndrome. Despite the presence of these predicted pathogenic variants in the human population, we identified no individuals homozygous for any biochemically verified or predicted pathogenic RECQL or RECQL5 variant. Nor did we find any individual heterozygous for known pathogenic variants in two or more of the disease-associated RECQ helicase genes BLM, RECQL4, or WRN. Several postulated RECQ helicase deficiency syndromes-RECQL or RECQL5 loss of function, or compound haploinsufficiency for the disease-associated RECQ helicases-may remain missing, as they likely incompatible with life.
Subject(s)
Genetic Association Studies , Genetics, Population , Mutation , RecQ Helicases/genetics , Computational Biology/methods , DNA Mutational Analysis , Databases, Nucleic Acid , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , ROC Curve , Software , Web BrowserABSTRACT
The African Diaspora in the Western Hemisphere represents one of the largest forced migrations in history and had a profound impact on genetic diversity in modern populations. To date, the fine-scale population structure of descendants of the African Diaspora remains largely uncharacterized. Here we present genetic variation from deeply sequenced genomes of 642 individuals from North and South American, Caribbean and West African populations, substantially increasing the lexicon of human genomic variation and suggesting much variation remains to be discovered in African-admixed populations in the Americas. We summarize genetic variation in these populations, quantifying the postcolonial sex-biased European gene flow across multiple regions. Moreover, we refine estimates on the burden of deleterious variants carried across populations and how this varies with African ancestry. Our data are an important resource for empowering disease mapping studies in African-admixed individuals and will facilitate gene discovery for diseases disproportionately affecting individuals of African ancestry.
Subject(s)
Black People/genetics , Gene Flow , Genome, Human , Human Migration , Base Sequence , DNA, Intergenic/genetics , Female , Genetic Heterogeneity , Geography , Humans , Male , Phylogeny , Polymorphism, Single Nucleotide/genetics , SexismABSTRACT
Identifying and characterizing genomic regions that are shared identical by descent (IBD) among individuals can yield insight into population history, facilitate the identification of adaptively evolving loci, and be an important tool in disease gene mapping. Although increasingly large collections of exome sequences have been generated, it is challenging to detect IBD segments in exomes, precluding many potentially informative downstream analyses. Here, we describe an approach, ExIBD, to robustly detect IBD segments in exome-sequencing data, rigorously evaluate its performance, and apply this method to high-coverage exomes from 6,515 European and African Americans. Furthermore, we show how IBD networks, constructed from patterns of pairwise IBD between individuals, and principles from graph theory provide insight into recent population history and reveal cryptic population structure in European Americans. Our results enable IBD analyses to be performed on exome data, which will expand the scope of inferences that can be made from existing massively large exome-sequencing datasets.
Subject(s)
Databases, Genetic , Exome , Genetics, Population/methods , Sequence Analysis, DNA , Black or African American/genetics , Genome, Human , Genomics , Genotyping Techniques , Humans , Models, Biological , Polymorphism, Single Nucleotide , White People/geneticsABSTRACT
Mutations in genes encoding autophagy proteins have been associated with human autoimmune diseases, suggesting that diversity in autophagy responses could be associated with disease susceptibility or severity. A cellular genome-wide association study (GWAS) screen was performed to explore normal human diversity in responses to rapamycin, a microbial product that induces autophagy. Cells from several human populations demonstrated variability in expression of a cell surface receptor, CD244 (SlamF4, 2B4), that correlated with changes in rapamycin-induced autophagy. High expression of CD244 and receptor activation with its endogenous ligand CD48 inhibited starvation- and rapamycin-induced autophagy by promoting association of CD244 with the autophagy complex proteins Vps34 and Beclin-1. The association of CD244 with this complex reduced Vps34 lipid kinase activity. Lack of CD244 is associated with auto-antibody production in mice, and lower expression of human CD244 has previously been implicated in severity of human rheumatoid arthritis and systemic lupus erythematosus, indicating that increased autophagy as a result of low levels of CD244 may alter disease outcomes.
Subject(s)
Autophagy/genetics , Gene Expression , Signaling Lymphocytic Activation Molecule Family/genetics , Beclin-1/metabolism , Class III Phosphatidylinositol 3-Kinases/metabolism , Genome-Wide Association Study , Humans , Signaling Lymphocytic Activation Molecule Family/metabolismABSTRACT
Non-allelic homologous recombination (NAHR) is one of the key mechanisms of DNA rearrangement. NAHR occurring between direct homologous repeats can generate genomic copy number variation (CNV) and make significant contributions to both genome evolution and human diseases such as cancer. Intriguingly, previous observations on the rare CNVs at certain genomic disorder loci suggested that NAHR frequency could be dependent on homology properties. However, such a correlation remains unclear at the other NAHR-mediated CNV loci, especially the common CNVs in human populations. Different from the rare CNVs associated with genomic disorders, it is challenging to identify de novo NAHR events at common CNV loci. Therefore, our previously proposed statistic M was employed in estimating relative mutation rate for the NAHR-mediated CNVs in human populations. By utilizing generalized regression neural network and principal component analysis in studying 4330 CNVs ascertained in 3 HapMap populations, we identified the CNVs mediated by NAHR between paired segmental duplications (SDs) and further revealed the correlations between SD properties and NAHR probability. SD length and inter-SD distance were shown to make major contributions to the occurrence of NAHR, whereas chromosomal position and sequence similarity of paired SDs are also involved in NAHR. An integrated effect of SD properties on NAHR frequency was revealed for the common CNVs in human populations. These observations can be well explained by ectopic synapsis in NAHR together with our proposed model of chromosomal compression/extension/looping (CCEL) for homology mis-pairing. Our findings showed the important roles of SDs in NAHR and human genomic evolution.
Subject(s)
DNA Copy Number Variations , Genome, Human , Homologous Recombination , Alleles , Chromosomes, Human/genetics , Chromosomes, Human/metabolism , Evolution, Molecular , Gene Rearrangement , Genetic Loci , Genomics , Humans , Models, Theoretical , Mutation Rate , Principal Component Analysis , Repetitive Sequences, Nucleic Acid , Segmental Duplications, Genomic , Sequence AlignmentABSTRACT
Understanding the genetic structure of human populations has important implications for the design and interpretation of disease mapping studies and reconstructing human evolutionary history. To date, inferences of human population structure have primarily been made with common variants. However, recent large-scale resequencing studies have shown an abundance of rare variation in humans, which may be particularly useful for making inferences of fine-scale population structure. To this end, we used an information theory framework and extensive coalescent simulations to rigorously quantify the informativeness of rare and common variation to detect signatures of fine-scale population structure. We show that rare variation affords unique insights into patterns of recent population structure. Furthermore, to empirically assess our theoretical findings, we analyzed high-coverage exome sequences in 6,515 European and African American individuals. As predicted, rare variants are more informative than common polymorphisms in revealing a distinct cluster of European-American individuals, and subsequent analyses demonstrate that these individuals are likely of Ashkenazi Jewish ancestry. Our results provide new insights into the population structure using rare variation, which will be an important factor to account for in rare variant association studies.
Subject(s)
Exome/genetics , Genetics, Population/methods , Ethnicity/genetics , Humans , Information Theory , Polymorphism, Single Nucleotide/genetics , Principal Component AnalysisABSTRACT
Neuropeptide substance P (SP) and reactive oxygen species (ROS) have been demonstrated to play an important role in psychological stress-induced alteration of hair cycle, the underlying mechanism remains unknown. The present study aims to investigate possible contribution of SP and ROS in chronic restraint stress (CRS, a chronic psychological stress model) induced abnormal of hair cycle and induction of autophagy. Mouse CRS model was applied for 18 days with or without treatment antioxidant Tempol (a free radical scavenger) or SP receptor (NK1) antagonist (RP67580). After CRS procedure, hair growth cycle, oxidative stress markers and skin tissue autophagy levels were analyzed by ELISA or western blot. Our results revealed that CRS reduced body weight gain, distance of movement and times of standing, affected hair cycle by prolonging the telogen stage and delaying subsequent anagen and catagen stage. In addition, CRS resulted in increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and increase of autophagy markers (microtubule-associated proteins, light chain 3-II, LC3-II, and Beclin-1) in mice skin. Treatment with Tempol restored GSH-Px activity, and significantly reduced increases of lipid peroxidation levels and LC3-II and Beclin-1 expressions, as well as normalized hair cycle. In addition; RP67580 also restored SOD and GSH-Px activities, and markedly reduced increases of lipid peroxidation levels and LC3-II and Beclin-1 expressions, and normalized hair cycle. Our study provides the first strong evidence for SP and ROS play a role not only in alteration of hair cycle but also in induction of autophagy in psychological stress model, suggesting autophagy may contribute to psychological stress-induced abnormal of hair cycle.
Subject(s)
Autophagy , Hair/growth & development , Oxidative Stress/physiology , Stress, Psychological/metabolism , Substance P/metabolism , Animals , Antioxidants/pharmacology , Blotting, Western/methods , Cyclic N-Oxides/pharmacology , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Glutathione Peroxidase/metabolism , Isoindoles , Lipid Peroxidation , Male , Mice , Mice, Inbred C57BL , Microtubule-Associated Proteins/metabolism , Neurokinin-1 Receptor Antagonists/pharmacology , Spin Labels , Superoxide Dismutase/metabolismABSTRACT
Whole-genome and exome data sets continue to be produced at a frenetic pace, resulting in massively large catalogs of human genomic variation. However, a clear picture of the characteristics and patterns of neutral and deleterious variation within and between populations has yet to emerge, given that recent large-scale sequencing studies have often emphasized different aspects of the data and sometimes appear to have conflicting conclusions. Here, we comprehensively studied characteristics of protein-coding variation in high-coverage exome sequence data from 6,515 European American (EA) and African American (AA) individuals. We developed an unbiased approach to identify putatively deleterious variants and investigated patterns of neutral and deleterious single-nucleotide variants and alleles between individuals and populations. We show that there are substantial differences in the composition of genotypes between EA and AA populations and that small but statistically significant differences exist in the average number of deleterious alleles carried by EA and AA individuals. Furthermore, we performed extensive simulations to delineate the temporal dynamics of deleterious alleles for a broad range of demographic models and use these data to inform the interpretation of empirical patterns of deleterious variation. Finally, we illustrate that the effects of demographic perturbations, such as bottlenecks and expansions, often manifest in opposing patterns of neutral and deleterious variation depending on whether the focus is on populations or individuals. Our results clarify seemingly disparate empirical characteristics of protein-coding variation and provide substantial insights into how natural selection and demographic history have patterned neutral and deleterious variation within and between populations.
Subject(s)
Black People/genetics , Exome/genetics , Exons/genetics , Genetics, Population , Polymorphism, Single Nucleotide/genetics , Proteins/genetics , White People/genetics , Africa/ethnology , Europe/ethnology , Evolution, Molecular , Genetic Drift , Genome, Human , Humans , Models, Theoretical , Selection, GeneticABSTRACT
Fanconi anemia (FA) is a human recessive genetic disease resulting from inactivating mutations in any of 16 FANC (Fanconi) genes. Individuals with FA are at high risk of developmental abnormalities, early bone marrow failure and leukemia. These are followed in the second and subsequent decades by a very high risk of carcinomas of the head and neck and anogenital region, and a small continuing risk of leukemia. In order to characterize base pair-level disease-associated (DA) and population genetic variation in FANC genes and the segregation of this variation in the human population, we identified 2948 unique FANC gene variants including 493 FA DA variants across 57,240 potential base pair variation sites in the 16 FANC genes. We then analyzed the segregation of this variation in the 7578 subjects included in the Exome Sequencing Project (ESP) and the 1000 Genomes Project (1KGP). There was a remarkably high frequency of FA DA variants in ESP/1KGP subjects: at least 1 FA DA variant was identified in 78.5% (5950 of 7578) individuals included in these two studies. Six widely used functional prediction algorithms correctly identified only a third of the known, DA FANC missense variants. We also identified FA DA variants that may be good candidates for different types of mutation-specific therapies. Our results demonstrate the power of direct DNA sequencing to detect, estimate the frequency of and follow the segregation of deleterious genetic variation in human populations.
Subject(s)
Exome , Fanconi Anemia Complementation Group Proteins/genetics , Fanconi Anemia/genetics , Genetic Variation , Multigene Family , Algorithms , BRCA2 Protein/genetics , DNA-Binding Proteins/genetics , Fanconi Anemia/pathology , Fanconi Anemia Complementation Group N Protein , Gene Expression , Genes, Recessive , Genome-Wide Association Study , High-Throughput Nucleotide Sequencing , Humans , Mutation Rate , Nuclear Proteins/genetics , RNA Helicases/genetics , Tumor Suppressor Proteins/geneticsABSTRACT
Demographic change of human populations is one of the central questions for delving into the past of human beings. To identify major population expansions related to male lineages, we sequenced 78 East Asian Y chromosomes at 3.9 Mbp of the non-recombining region, discovered >4,000 new SNPs, and identified many new clades. The relative divergence dates can be estimated much more precisely using a molecular clock. We found that all the Paleolithic divergences were binary; however, three strong star-like Neolithic expansions at â¼6 kya (thousand years ago) (assuming a constant substitution rate of 1×10(-9)/bp/year) indicates that â¼40% of modern Chinese are patrilineal descendants of only three super-grandfathers at that time. This observation suggests that the main patrilineal expansion in China occurred in the Neolithic Era and might be related to the development of agriculture.