Cohort studies are costly and time consuming.They require not only laboratory equipment and assays but also collaboration from participants and health agencies.Due to cost constraints,they are often confined to a spec...Cohort studies are costly and time consuming.They require not only laboratory equipment and assays but also collaboration from participants and health agencies.Due to cost constraints,they are often confined to a specific population.Nevertheless,they play a crucial role in providing fundamental insights for medical advancements,shedding light on the origins of diseases,and acting in socioeconomic influence in policy making.展开更多
To unravel the genetic mechanisms of disease and physiological traits,it requires comprehensive sequencing analysis of large sample size in Chinese populations.Here,we report the primary results of the Chinese Academy...To unravel the genetic mechanisms of disease and physiological traits,it requires comprehensive sequencing analysis of large sample size in Chinese populations.Here,we report the primary results of the Chinese Academy of Sciences Precision Medicine Initiative(CASPMI)project launched by the Chinese Academy of Sciences,including the de novo assembly of a northern Han reference genome(NH1.0)and whole genome analyses of 597 healthy people coming from most areas in China.Given the two existing reference genomes for Han Chinese(YH and HX1)were both from the south,we constructed NH1.0,a new reference genome from a northern individual,by combining the sequencing strategies of PacBio,10×Genomics,and Bionano mapping.Using this integrated approach,we obtained an N50 scaffold size of 46.63 Mb for the NH1.0 genome and performed a comparative genome analysis of NH1.0 with YH and HX1.In order to generate a genomic variation map of Chinese populations,we performed the whole-genome sequencing of 597 participants and identified 24.85 million(M)single nucleotide variants(SNVs),3.85 M small indels,and 106,382 structural variations.In the association analysis with collected phenotypes,we found that the T allele of rs1549293 in KAT8 significantly correlated with the waist circumference in northern Han males.Moreover,significant genetic diversity in MTHFR,TCN2,FADS1,and FADS2,which associate with circulating folate,vitamin B12,or lipid metabolism,was observed between northerners and southerners.Especially,for the homocysteine-increasing allele of rs1801133(MTHFR 677T),we hypothesize that there exists a “comfort”zone for a high frequency of 677T between latitudes of 35–45 degree North.Taken together,our results provide a high-quality northern Han reference genome and novel population-specific data sets of genetic variants for use in the personalized and precision medicine.展开更多
Hepatitis B virus(HBV),one of the well-known DNA oncogenic viruses,is the leading cause of hepatocellular carcinoma(HCC).In infected hepatocytes,HBV DNA can be integrated into the host genome through an insertional mu...Hepatitis B virus(HBV),one of the well-known DNA oncogenic viruses,is the leading cause of hepatocellular carcinoma(HCC).In infected hepatocytes,HBV DNA can be integrated into the host genome through an insertional mutagenesis process inducing tumorigenesis.Dissection of the genomic features surrounding integration sites will deepen our understanding of mechanisms underlying integration.Moreover,the quantity and biological activity of integration sites may reflect the DNA damage within affected cells or the potential survival benefits they may confer.The wellknown human genomic features include repeat elements,particular regions(such as telomeres),and frequently interrupted genes(e.g.,telomerase reverse transcriptase[i.e.TERT],lysine methyltransferase 2B[i.e.KMT2B],cyclin E1[CCNE1],and cyclin A2[CCNA2]).Consequently,distinct genomic features within diverse integrations differentiate their biological functions.Meanwhile,accumulating evidence has shown that viral proteins produced by integrants may cause cell damage even after the suppression of HBV replication.The integration-derived gene products can also serve as tumor markers,promoting the development of novel therapeutic strategies for HCC.Viral integrants can be single copy or multiple copies of different fragments with complicated rearrangement,which warrants elucidation of the whole viral integrant arrangement in future studies.All of these considerations underlie an urgent need to develop novel methodology and technology for sequence characterization and function evaluation of integration events in chronic hepatitis B-associated disease progression by monitoring both host genomic features and viral integrants.This endeavor may also serve as a promising solution for evaluating the risk of tumorigenesis and as a companion diagnostic for designing therapeutic strategies targeting integration-related disease complications.展开更多
The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two ...The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two Chinese isolates with that of a reference strain（P1/7）. In the89 K genomic island that is specific to these Chinese isolates, a toxin–antitoxin system showed relatively high levels of transcription among the S. suis. The known virulence factors with high transcriptional activity in these two highly-pathogenic strains are mainly involved in adhesion, biofilm formation, hemolysis and the synthesis and transport of the outer membrane protein. Furthermore,our analysis of novel transcripts identified over 50 protein-coding genes with one of them encoding a toxin protein. We also predicted over 30 small RNAs（s RNAs） in each strain, and most of them are involved in riboswitches. We found that six s RNA candidates that are related to bacterial virulence, including csp A and rli38, are specific to Chinese isolates. These results provide insight into the factors responsible for the difference in virulence among the different S. suis 2 isolates.展开更多
Esophageal squamous cell carcinoma （ESCC） has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exon...Esophageal squamous cell carcinoma （ESCC） has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exonic mutations and structural alterations. The clinical implications of these genetic alterations were also analyzed. Exome sequencing and verification were performed for nine pairs of ESCC and the matched blood samples, followed by validation with additional sam- ples using Sanger sequencing. Whole-genomc SNP arrays were employed to detect copy number alteration （CNA） and loss of heterozygosity （LOH） in 55 cases, including the nine ESCC samples subjected to exome sequencing. A total of 108 non-synonymous somatic mutations （NSSMs） in 102 genes were verified in nine patients. The chromatin modification process was found to be enriched in our gene ontology （GO） analysis. Tumor genomes with TP53 mutations were signifi- cantly more unstable than those without TP53 mutations. In terms of the landscape of genomic alterations, deletion of 9p21.3 covering CDKN2A/2B （30.9%）, amplification of 1 1q13.3 covering CCND1 （30.9%）, and TP53 point mutation （50.9%） occurred in two-thirds of the cases. These results suggest that the deregulation of the G1 phase during the cell cycle is a key event in ESCC. Furthermore, six minimal common regions were found to be significantly altered in ESCC samples and three of them, 9p21.3, 7p 11.2, and 3p 12.1, were associated with lymph node metastasis. With the high correlation of TP53 mutation and genomic instability in ESCC, the amplification of CCND1, the deletion of CDKN2A/2B, and the somatic mutation of TP53 appear to play pivotal roles via G1 deregulation and therefore helps to classify this cancer into different genomic subtypes. These findings provide clinical significance that could be useful in future molecular diagnoses and therapeutic targeting.展开更多
Humans have been exposed to many environmental challenges since their evolutionary origins in Africa and subsequent migrations to the rest of the world. A severe environmental challenge to human migrants was hypoxia c...Humans have been exposed to many environmental challenges since their evolutionary origins in Africa and subsequent migrations to the rest of the world. A severe environmental challenge to human migrants was hypoxia caused by low barometric oxygen pressure at high altitudes. Several genome-wide scans have elucidated the genetic basis of human high-altitude adaptations.However, the dearth of functional variant information has led to the successful association of only a few candidate genes. In the present study, we employed a candidate gene approach and re-sequenced the EDAR locus in 45 Tibetan individuals to identify mutations involved in hypoxia adaptation. We identified 10 and five quantitative trait-associated mutations for oxygen saturation (SaO_2) and blood platelet count, respectively, at the EDAR locus. Among these, rs10865026 and rs3749110 (associated with SaO_2 and platelet count, respectively) were identified as functional candidate targets. These data demonstrate that EDAR has undergone natural selection in recent human history and indicate an important role of EDAR variants in Tibetan high-altitude adaptations.展开更多
The global "myopia boom" has raised significant international concerns. Despite a higher myopia prevalence in Asia, previous large-scale genome-wide association studies(GWASs) were mostly based on European d...The global "myopia boom" has raised significant international concerns. Despite a higher myopia prevalence in Asia, previous large-scale genome-wide association studies(GWASs) were mostly based on European descendants. Here, we report a GWAS of spherical equivalent(SE) in 1852 Chinese Han individuals with extreme SE from Guangzhou(631 <-6.00 D and 574 > 0.00 D) and Wenzhou(593 <-6.00 D and54 >-1.75 D), followed by a replication study in two independent cohorts with totaling 3538 East Asian individuals. The discovery GWAS and meta-analysis identify three novel loci, which show genome-wide significant associations with SE, including 1 q25.2 FAM163 A, 10 p11.22 NRP1/PRAD3, and 10 p11.21 ANKRD30 A/MTRNR2 L7, together explaining 3.34% of SE variance. 10 p11.21 is successfully replicated.The allele frequencies of all three loci show significant differences between major continental groups(P < 0.001). The SE reducing(more myopic) allele of rs10913877(1 q25.2 FAM163 A) demonstrates the highest frequency in East Asians and much lower frequencies in Europeans and Africans(EAS = 0.60,EUR = 0.20, and AFR = 0.18). The gene-based analysis additionally identifies three novel genes associated with SE, including EI24, LHX5, and ARPP19. These results provide new insights into myopia pathogenesis and indicate the role of genetic heterogeneity in myopia epidemiology among different ethnicities.展开更多
Postzygotic mutations are acquired in normal tissues throughout an individual’s lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using...Postzygotic mutations are acquired in normal tissues throughout an individual’s lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using optimized ultra-deep exome sequencing of the time-series samples from the same volunteer as well as the samples from different individuals.In blood,sperm,and muscle cells,we resolved three common types of mutational signatures.Signatures A and B represent clocklike mutational processes,and the polymorphisms of epigenetic regulation genes influence the proportion of signature B in mutation profiles.Notably,signature C,characterized by C>T transitions at GpCpN sites,tends to be a feature of diverse normal tissues.Mutations of this type are likely to occur early during embryonic development,supported by their relatively high allelic frequencies,presence in multiple tissues,and decrease in occurrence with age.Almost none of the public datasets for tumors feature this signature,except for 19.6%of samples of clear cell renal cell carcinoma with increased activation of the hypoxia-inducible factor 1(HIF-1)signaling pathway.Moreover,the accumulation of signature C in the mutation profile was accelerated in a human embryonic stem cell line with drug-induced activation of HIF-1α.Thus,embryonic hypoxia may explain this novel signature across multiple normal tissues.Our study suggests that hypoxic condition in an early stage of embryonic development is a crucial factor inducing C>T transitions at GpCpN sites;and individuals’genetic background may also influence their postzygotic mutation profiles.展开更多
The chromosome 17q21.31 inversion is a 900-kb common structural polymorphism found primarily in European population. Although the genetic flux within inversion region was assumed to be considerable suppressed, it is s...The chromosome 17q21.31 inversion is a 900-kb common structural polymorphism found primarily in European population. Although the genetic flux within inversion region was assumed to be considerable suppressed, it is still unclear about the details of genetic exchange between the H1 （non-inverted sequence） and H2 （inverted sequence） haplotypes of this inversion. Here we describe a refmed map of genetic exchanges between pairs of gene arrangements within the 17q21.31 region. Using HapMap phase II data of 1,546 single nucleotide polymorphisms, we successfully deduced 96 H1 and 24 H2 haplotypes in European samples by neighbor-joining tree reconstruction. Furthermore, we identified 15 and 26 candidate tracts with reciprocal and non-reciprocal genetic exchanges, respectively. In all 15 regions harboring reciprocal exchange, haplotypes reconstructed by clone sequencing did not support these exchange events, suggesting that such signals of exchange between two sister chromosomes in certain heterozygous individual were caused by phasing error regions. On the other hand, the finished clone sequencing across 4 of 26 tracts with non-reciprocal genetic flux confirmed that this kind of genetic exchange was caused by gene conversion. In summary, as crossover between pairs of gene arrangements had been considerably suppressed, gene conversion might be the most important mechanism for genetic exchange at 17q21.31.展开更多
Autoantibodies from patients with various connective tissue diseases have been shown to be specific probes that can detect cellular structures, including centrosome, centromere/kineto- chore, spliceosome, Golgi comple...Autoantibodies from patients with various connective tissue diseases have been shown to be specific probes that can detect cellular structures, including centrosome, centromere/kineto- chore, spliceosome, Golgi complex and the rough endoplasmic reticulum （Louvard et al., 1982; Rattner et al., 1998;展开更多
文摘Cohort studies are costly and time consuming.They require not only laboratory equipment and assays but also collaboration from participants and health agencies.Due to cost constraints,they are often confined to a specific population.Nevertheless,they play a crucial role in providing fundamental insights for medical advancements,shedding light on the origins of diseases,and acting in socioeconomic influence in policy making.
基金supported by the grants of Key Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-L14 awarded to CZ)the National Key R&D Program of China from the Ministry of Science and Technology of China(Grant No.2016YFB0201702 awarded to JX,as well as Grant Nos.2016YFC0901701 and 2018YFC0910700 awarded to XF)
文摘To unravel the genetic mechanisms of disease and physiological traits,it requires comprehensive sequencing analysis of large sample size in Chinese populations.Here,we report the primary results of the Chinese Academy of Sciences Precision Medicine Initiative(CASPMI)project launched by the Chinese Academy of Sciences,including the de novo assembly of a northern Han reference genome(NH1.0)and whole genome analyses of 597 healthy people coming from most areas in China.Given the two existing reference genomes for Han Chinese(YH and HX1)were both from the south,we constructed NH1.0,a new reference genome from a northern individual,by combining the sequencing strategies of PacBio,10×Genomics,and Bionano mapping.Using this integrated approach,we obtained an N50 scaffold size of 46.63 Mb for the NH1.0 genome and performed a comparative genome analysis of NH1.0 with YH and HX1.In order to generate a genomic variation map of Chinese populations,we performed the whole-genome sequencing of 597 participants and identified 24.85 million(M)single nucleotide variants(SNVs),3.85 M small indels,and 106,382 structural variations.In the association analysis with collected phenotypes,we found that the T allele of rs1549293 in KAT8 significantly correlated with the waist circumference in northern Han males.Moreover,significant genetic diversity in MTHFR,TCN2,FADS1,and FADS2,which associate with circulating folate,vitamin B12,or lipid metabolism,was observed between northerners and southerners.Especially,for the homocysteine-increasing allele of rs1801133(MTHFR 677T),we hypothesize that there exists a “comfort”zone for a high frequency of 677T between latitudes of 35–45 degree North.Taken together,our results provide a high-quality northern Han reference genome and novel population-specific data sets of genetic variants for use in the personalized and precision medicine.
基金This work was supported by the 111Project(Project No.:B13003)Innovation Promotion Association CAS(2016098)National Natural Science Foundation of China(81201700)to D.Z。
文摘Hepatitis B virus(HBV),one of the well-known DNA oncogenic viruses,is the leading cause of hepatocellular carcinoma(HCC).In infected hepatocytes,HBV DNA can be integrated into the host genome through an insertional mutagenesis process inducing tumorigenesis.Dissection of the genomic features surrounding integration sites will deepen our understanding of mechanisms underlying integration.Moreover,the quantity and biological activity of integration sites may reflect the DNA damage within affected cells or the potential survival benefits they may confer.The wellknown human genomic features include repeat elements,particular regions(such as telomeres),and frequently interrupted genes(e.g.,telomerase reverse transcriptase[i.e.TERT],lysine methyltransferase 2B[i.e.KMT2B],cyclin E1[CCNE1],and cyclin A2[CCNA2]).Consequently,distinct genomic features within diverse integrations differentiate their biological functions.Meanwhile,accumulating evidence has shown that viral proteins produced by integrants may cause cell damage even after the suppression of HBV replication.The integration-derived gene products can also serve as tumor markers,promoting the development of novel therapeutic strategies for HCC.Viral integrants can be single copy or multiple copies of different fragments with complicated rearrangement,which warrants elucidation of the whole viral integrant arrangement in future studies.All of these considerations underlie an urgent need to develop novel methodology and technology for sequence characterization and function evaluation of integration events in chronic hepatitis B-associated disease progression by monitoring both host genomic features and viral integrants.This endeavor may also serve as a promising solution for evaluating the risk of tumorigenesis and as a companion diagnostic for designing therapeutic strategies targeting integration-related disease complications.
基金supported by the CAS Key Laboratory of Pathogenic Microbiology and Immunology of China (Grant No. 2009CASPMI-007) to DZthe National Natural Science Foundation of China (Grant No. 81201700) to DZ
文摘The Streptococcus suis serotype 2（S. suis 2） isolates 05ZYH33 and 98HAH33 have caused severe human infections in China. Using a strand-specific RNA-seq analysis, we compared the in vitro transcriptomes of these two Chinese isolates with that of a reference strain（P1/7）. In the89 K genomic island that is specific to these Chinese isolates, a toxin–antitoxin system showed relatively high levels of transcription among the S. suis. The known virulence factors with high transcriptional activity in these two highly-pathogenic strains are mainly involved in adhesion, biofilm formation, hemolysis and the synthesis and transport of the outer membrane protein. Furthermore,our analysis of novel transcripts identified over 50 protein-coding genes with one of them encoding a toxin protein. We also predicted over 30 small RNAs（s RNAs） in each strain, and most of them are involved in riboswitches. We found that six s RNA candidates that are related to bacterial virulence, including csp A and rli38, are specific to Chinese isolates. These results provide insight into the factors responsible for the difference in virulence among the different S. suis 2 isolates.
基金supported by the National Basic Research Program of China from the National Ministry of Science and Technology(973 Program)to YK(Grant No.2011CB504300)and to HC(Grant No.2012CB910800)the National Natural Science Foundation of China(Grant No.30930102)to YK+3 种基金the National High-tech R&D Program of China(863 ProgramGrant No.2012AA022502)Key Research Program of the Chinese Academy of Sciences of China(Grant No.KJZD-EW-L06-2)to CZthe Open Fund of MOE Key Laboratory of Carcinogenesis and Translational Research(Grant No.2014KAIFANG-4)to JB
文摘Esophageal squamous cell carcinoma （ESCC） has a high mortality rate. To determine the molecular basis of ESCC development, this study sought to identify characteristic genome-wide alterations in ESCC, including exonic mutations and structural alterations. The clinical implications of these genetic alterations were also analyzed. Exome sequencing and verification were performed for nine pairs of ESCC and the matched blood samples, followed by validation with additional sam- ples using Sanger sequencing. Whole-genomc SNP arrays were employed to detect copy number alteration （CNA） and loss of heterozygosity （LOH） in 55 cases, including the nine ESCC samples subjected to exome sequencing. A total of 108 non-synonymous somatic mutations （NSSMs） in 102 genes were verified in nine patients. The chromatin modification process was found to be enriched in our gene ontology （GO） analysis. Tumor genomes with TP53 mutations were signifi- cantly more unstable than those without TP53 mutations. In terms of the landscape of genomic alterations, deletion of 9p21.3 covering CDKN2A/2B （30.9%）, amplification of 1 1q13.3 covering CCND1 （30.9%）, and TP53 point mutation （50.9%） occurred in two-thirds of the cases. These results suggest that the deregulation of the G1 phase during the cell cycle is a key event in ESCC. Furthermore, six minimal common regions were found to be significantly altered in ESCC samples and three of them, 9p21.3, 7p 11.2, and 3p 12.1, were associated with lymph node metastasis. With the high correlation of TP53 mutation and genomic instability in ESCC, the amplification of CCND1, the deletion of CDKN2A/2B, and the somatic mutation of TP53 appear to play pivotal roles via G1 deregulation and therefore helps to classify this cancer into different genomic subtypes. These findings provide clinical significance that could be useful in future molecular diagnoses and therapeutic targeting.
基金supported by the National Natural Science Foundation of China (91131905, 30890030)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB13020500)Weng Hongwu Original Scientific Research Foundation, Peking University
文摘Humans have been exposed to many environmental challenges since their evolutionary origins in Africa and subsequent migrations to the rest of the world. A severe environmental challenge to human migrants was hypoxia caused by low barometric oxygen pressure at high altitudes. Several genome-wide scans have elucidated the genetic basis of human high-altitude adaptations.However, the dearth of functional variant information has led to the successful association of only a few candidate genes. In the present study, we employed a candidate gene approach and re-sequenced the EDAR locus in 45 Tibetan individuals to identify mutations involved in hypoxia adaptation. We identified 10 and five quantitative trait-associated mutations for oxygen saturation (SaO_2) and blood platelet count, respectively, at the EDAR locus. Among these, rs10865026 and rs3749110 (associated with SaO_2 and platelet count, respectively) were identified as functional candidate targets. These data demonstrate that EDAR has undergone natural selection in recent human history and indicate an important role of EDAR variants in Tibetan high-altitude adaptations.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB38010400)National Key R&D Program of China (2018YFC0116500)+4 种基金Science and Technology Service Network Initiative of Chinese Academy of Sciences (KFJSTS-ZDTP-079)Science and Technology Planning Project of Guangdong Province (2013B20400003)the Fundamental Research Funds of the State Key Laboratory of Ophthalmologythe Open Project of Key Laboratory of Genomic and Precision Medicine of the CASsupported by the China Scholarship Council (CSC) and China Postdoctoral Science Foundation (2019TQ0365)。
文摘The global "myopia boom" has raised significant international concerns. Despite a higher myopia prevalence in Asia, previous large-scale genome-wide association studies(GWASs) were mostly based on European descendants. Here, we report a GWAS of spherical equivalent(SE) in 1852 Chinese Han individuals with extreme SE from Guangzhou(631 <-6.00 D and 574 > 0.00 D) and Wenzhou(593 <-6.00 D and54 >-1.75 D), followed by a replication study in two independent cohorts with totaling 3538 East Asian individuals. The discovery GWAS and meta-analysis identify three novel loci, which show genome-wide significant associations with SE, including 1 q25.2 FAM163 A, 10 p11.22 NRP1/PRAD3, and 10 p11.21 ANKRD30 A/MTRNR2 L7, together explaining 3.34% of SE variance. 10 p11.21 is successfully replicated.The allele frequencies of all three loci show significant differences between major continental groups(P < 0.001). The SE reducing(more myopic) allele of rs10913877(1 q25.2 FAM163 A) demonstrates the highest frequency in East Asians and much lower frequencies in Europeans and Africans(EAS = 0.60,EUR = 0.20, and AFR = 0.18). The gene-based analysis additionally identifies three novel genes associated with SE, including EI24, LHX5, and ARPP19. These results provide new insights into myopia pathogenesis and indicate the role of genetic heterogeneity in myopia epidemiology among different ethnicities.
基金supported by the grants from the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB13020500)the National Natural Science Foundation of China(NSFC)(Grant Nos.91131905,31471199,and 91631304)+3 种基金the Key Research Program of Chinese Academy of Sciences(Grant No.KJZD-EW-L14 to CZ)the NSFC(Grant Nos.31440057 and 31701081 to WC)the 111 Project(Grant No.B13003 to WC and DZ)the Innovation Promotion Association of Chinese Academy of Sciences(Grant Nos.2016098 to DZ and 2019103 to AC)。
文摘Postzygotic mutations are acquired in normal tissues throughout an individual’s lifetime and hold clues for identifying mutagenic factors.Here,we investigated postzygotic mutation spectra of healthy individuals using optimized ultra-deep exome sequencing of the time-series samples from the same volunteer as well as the samples from different individuals.In blood,sperm,and muscle cells,we resolved three common types of mutational signatures.Signatures A and B represent clocklike mutational processes,and the polymorphisms of epigenetic regulation genes influence the proportion of signature B in mutation profiles.Notably,signature C,characterized by C>T transitions at GpCpN sites,tends to be a feature of diverse normal tissues.Mutations of this type are likely to occur early during embryonic development,supported by their relatively high allelic frequencies,presence in multiple tissues,and decrease in occurrence with age.Almost none of the public datasets for tumors feature this signature,except for 19.6%of samples of clear cell renal cell carcinoma with increased activation of the hypoxia-inducible factor 1(HIF-1)signaling pathway.Moreover,the accumulation of signature C in the mutation profile was accelerated in a human embryonic stem cell line with drug-induced activation of HIF-1α.Thus,embryonic hypoxia may explain this novel signature across multiple normal tissues.Our study suggests that hypoxic condition in an early stage of embryonic development is a crucial factor inducing C>T transitions at GpCpN sites;and individuals’genetic background may also influence their postzygotic mutation profiles.
基金supported by the National Natural Science Foundation of China(No.30871348,30700470,30890030 and 30890031)Educational Department of Jiangxi Province(No.GJJ10303)
文摘The chromosome 17q21.31 inversion is a 900-kb common structural polymorphism found primarily in European population. Although the genetic flux within inversion region was assumed to be considerable suppressed, it is still unclear about the details of genetic exchange between the H1 （non-inverted sequence） and H2 （inverted sequence） haplotypes of this inversion. Here we describe a refmed map of genetic exchanges between pairs of gene arrangements within the 17q21.31 region. Using HapMap phase II data of 1,546 single nucleotide polymorphisms, we successfully deduced 96 H1 and 24 H2 haplotypes in European samples by neighbor-joining tree reconstruction. Furthermore, we identified 15 and 26 candidate tracts with reciprocal and non-reciprocal genetic exchanges, respectively. In all 15 regions harboring reciprocal exchange, haplotypes reconstructed by clone sequencing did not support these exchange events, suggesting that such signals of exchange between two sister chromosomes in certain heterozygous individual were caused by phasing error regions. On the other hand, the finished clone sequencing across 4 of 26 tracts with non-reciprocal genetic flux confirmed that this kind of genetic exchange was caused by gene conversion. In summary, as crossover between pairs of gene arrangements had been considerably suppressed, gene conversion might be the most important mechanism for genetic exchange at 17q21.31.
基金supported by the grants from the Ministry of Science and Technology (No. 2012AA022502 to C.Z.)the National Science Foundation of China (Nos. 81101490 to G.L., 31171371 to D.H.)
文摘Autoantibodies from patients with various connective tissue diseases have been shown to be specific probes that can detect cellular structures, including centrosome, centromere/kineto- chore, spliceosome, Golgi complex and the rough endoplasmic reticulum （Louvard et al., 1982; Rattner et al., 1998;
