Type 2 diabetes(T2D) is a common metabolic disorder which is caused by multiple genetic perturbations affecting different biological pathways. Identifying genetic factors modulating the susceptibility of this complex ...Type 2 diabetes(T2D) is a common metabolic disorder which is caused by multiple genetic perturbations affecting different biological pathways. Identifying genetic factors modulating the susceptibility of this complex heterogeneous metabolic phenotype in different ethnic and racial groups remains challenging. Despite recent success, the functional role of the T2D susceptibility variants implicated by genome-wide association studies(GWAS) remains largely unknown. Genetic dissection of transcript abundance or expression quantitative trait(eQTL) analysis unravels the genomic architecture of regulatory variants. Availability of eQTL information from tissues relevant for glucose homeostasis in humans opens a new avenue to prioritize GWASimplicated variants that may be involved in triggering a causal chain of events leading to T2D. In this article, we review the progress made in the field of eQTL research and knowledge gained from those studies in understanding transcription regulatory mechanisms in human subjects. We highlight several novel approaches that can integrate eQTL analysis with multiple layers of biological information to identify ethnic-specific causal variants and gene-environment interactions relevant to T2D pathogenesis. Finally, we discuss how the eQTL analysis mediated search for "missing heritability" may lead us to novel biological and molecular mechanisms involved in susceptibility to T2D.展开更多
Alzheimer's disease(AD)is affected by genetic factors.Polymorphisms in the glutathione S-transfe rase omega-1(Gsto1)gene have been shown by genetic correlation analyses performed in different ethnic populations to...Alzheimer's disease(AD)is affected by genetic factors.Polymorphisms in the glutathione S-transfe rase omega-1(Gsto1)gene have been shown by genetic correlation analyses performed in different ethnic populations to be genetic risk factors for AD.Gene expression profile data from BXD recombinant inbred mice were used in combination with genetic and bioinformatic analyses to chara cterize the mechanisms underlying regulation of Gstol variation regulation and to identify network membe rs that may contribute to AD risk or progression.Allele-specific assays confirmed that variation in Gstol expression is controlled by cis-expression quantitative trait loci.We found that Gstol mRNA levels were related to several central nervous system traits,such as glial acidic fibrillary protein levels in the caudate putamen,co rtical gray matter volume,and hippocampus mossy fiber pathway volume.We identified 2168 genes whose expression was highly correlated with that of Gsto1.Some genes were enriched for the most common neurodegenerative diseases.Some Gsto1-related genes identified in this study had previously been identified as susceptibility genes for AD,such as APP,Grin2 b,Ide,and Psenen.To evaluate the relationships between Gstol and candidate network members,we transfected astrocytes with Gstol siRNA and assessed the effect on putative downstream effecto rs.We confirmed that knockdown of Gstol had a significant influence on Pa2g4 expression,suggesting that Pa2g4 may be a downstream effector of Gstol,and that both genes intera ct with other genes in a network during AD pathogenesis.展开更多
Alternative splicing exists in most multi-exonic genes,and exploring these complex alternative splicing events and their resultant isoform expressions is essential.However,it has become conventional that RNA sequencin...Alternative splicing exists in most multi-exonic genes,and exploring these complex alternative splicing events and their resultant isoform expressions is essential.However,it has become conventional that RNA sequencing results have often been summarized into gene-level expression counts mainly due to the multiple ambiguous mapping of reads at highly similar regions.Transcript-level quantification and interpretation are often overlooked,and biological interpretations are often deduced based on combined transcript information at the gene level.Here,for the most variable tissue of alternative splicing,the brain,we estimate isoform expressions in 1,191 samples collected by the Genotype-Tissue Expression(GTEx)Consortium using a powerful method that we previously developed.We perform genome-wide association scans on the isoform ratios per gene and identify isoform-ratio quantitative trait loci(irQTL),which could not be detected by studying gene-level expressions alone.By analyzing the genetic architecture of the irQTL,we show that isoform ratios regulate edu-cational attainment via multiple tissues including the frontal cortex(BA9),cortex,cervical spinal cord,and hippocampus.These tissues are also associated with different neuro-related traits,including Alzheimer’s or dementia,mood swings,sleep duration,alcohol intake,intelligence,anxiety or depression,etc.Mendelian randomization(MR)analysis revealed 1,139 pairs of isoforms and neuro-related traits with plausible causal relationships,showing much stronger causal effects than on general diseases measured in the UK Biobank(UKB).Our results highlight essential transcript-level biomarkers in the human brain for neuro-related complex traits and diseases,which could be missed by merely investigating overall gene expressions.展开更多
Background and aim:A genome-wide association study has indicated the association of numerous genes in the 6p21.3 region with chronic hepatitis B virus(HBV)infection.In this study,we screened 12 representative single-n...Background and aim:A genome-wide association study has indicated the association of numerous genes in the 6p21.3 region with chronic hepatitis B virus(HBV)infection.In this study,we screened 12 representative single-nucleotide polymorphisms(SNPs)from the 6p21.3 region and investigated their association with the risk of chronic hepatitis B(CHB)to better understand the molecular etiology un-derlying CHB risk in the Han Chinese population.Methods:Between March 2021 and November 2022,we included 183 patients with CHB(case group)and 196 with natural HBV clearance(control group).Allele typing of the selected SNPs was performed using snapshot technology.The correlation between the 12 chosen SNPs and the risk of chronic HBV infection was examined using binary logistic regression analysis.Interacting genes of the variants were identified,and expression quantitative trait loci(eQTL)were analyzed using the 3DSNP database.Results:We validated 12 previously reported CHB susceptibility sites,including rs1419881 of tran-scription factor 19(TCF19),rs3130542 and rs2853953 of human leukocyte antigen(HLA)-C,rs652888 of euchromatic histone-lysine-methyltransferase 2(EHMT2),rs2856718,rs9276370,rs7756516,and rs7453920 of HLA-DQ,rs378352 of HLA-DOA,and rs3077,rs9277535,and rs9366816 of HLA-DP.Logistic regression analyses revealed that polymorphisms such as rs9276370,rs7756516,rs7453920,rs3077,rs9277535,and rs9366816 were positively correlated with natural HBV clearance in the dominant model.Conversely,rs3130542 and rs378352 were identified as risk factors for CHB.Haplotype analysis revealed that rs9276370,rs7756516,and rs7453920 in HLA-DQ were TTG and GCA haplotypes.Although the TTG haplotype was positively correlated with a higher risk of CHB,the GCA haplotype significantly influenced the natural clearance of HBV.Bioinformatics analysis demonstrated that rs378352,rs3077,and rs9366816 were located within enhancer states;rs3077 and rs9366816 overlapped with nine tran-scription factor-binding sites,whereas rs378352 altered five sequence motifs.Furthermore,eQTL analysis demonstrated the functional tendencies of eight statistically significant SNPs(rs3130542,rs9276370,rs7756516,rs7453920,rs378352,rs3077,rs9277535,and rs9366816).Conclusions:Genetic variations within the 6p21.3 region were associated with chronic HBV infection in the Han Chinese population in southern China.Furthermore,the GCA haplotype including rs9276370,rs7756516,and rs7453920 of HLA-DQ contributed significantly to natural HBV clearance,implying that multiple SNPs exert a cumulative allelic effect on HBV infection.展开更多
Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） popul...Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） population of 168 lines, which was generated from the cross between two elite Chinese common wheat （Triticum aestivum L.） varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat （SSR） and 22 expressed sequence tag （EST）-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.展开更多
Gene expression regulation plays an important role in controlling plant phenotypes and adaptation. Here, we report a comprehensive assessment of gene expression variation through the transcriptome analyses of a large ...Gene expression regulation plays an important role in controlling plant phenotypes and adaptation. Here, we report a comprehensive assessment of gene expression variation through the transcriptome analyses of a large maize-teosinte experimental population. Genome-wide mapping identified 25 660 expression quantitative trait loci （eQTL） for 17 311 genes, capturing an unprecedented range of expression variation. We found that local eQTL were more frequently mapped to adjacent genes, displaying a mode of expression piggybacking, which consequently created co-regulated gene clusters. Genes within the co-regulated gene clusters tend to have relevant functions and shared chromatin modifications. Distant eQTL formed 125 significant distant eQTL hotspots with their targets significantly enriched in specific functional cate- gories. By integrating different sources of information, we identified putative trans- regulators for a variety of metabolic pathways. We demonstrated that the bHLH transcription factor R1 and hexokinase HEX9 might act as crucial regulators for flavonoid biosynthesis and glycolysis, respectively. Moreover, we showed that domestication or improvement has significantly affected global gene expression, with many genes targeted by selection. Of particular interest, the Bx genes for benzoxazinoid biosynthesis may have undergone coordinated cis-regulatory divergence between maize and teosinte, and a transposon insertion that inactivates Bx12 was under strong selection as maize spread into temperate environments with a distinct herbivore community.展开更多
Genome-wide association studies(GWAS)have identified thousands of genomic loci associated with complex diseases and traits,including cancer.The vast majority of common traitassociated variants identified via GWAS fall...Genome-wide association studies(GWAS)have identified thousands of genomic loci associated with complex diseases and traits,including cancer.The vast majority of common traitassociated variants identified via GWAS fall in non-coding regions of the genome,posing a challenge in elucidating the causal variants,genes,and mechanisms involved.Expression quantitative trait locus(eQTL)and other molecular QTL studies have been valuable resources in identifying candidate causal genes from GWAS loci through statistical colocalization methods.While QTL colocalization is becoming a standard analysis in post-GWAS investigation,an easy web tool for users to perform formal colocalization analyses with either user-provided or public GWAS and eQTL datasets has been lacking.Here,we present ezQTL,a web-based bioinformatic application to interactively visualize and analyze genetic association data such as GWAS loci and molecular QTLs under different linkage disequilibrium(LD)patterns(1000 Genomes Project,UK Biobank,or user-provided data).This application allows users to perform data quality control for variants matched between different datasets,LD visualization,and two-trait colocalization analyses using two state-of-the-art methodologies(eCAVIAR and HyPrColoc),including batch processing.ezQTL is a free and publicly available cross-platform web tool,which can be accessed online at https://analysistools.cancer.gov/ezqtl.展开更多
Rheumatic diseases differ in severity and outcome across ethnic groups.Although genetic predisposition is an important factor influencing the development of rheumatic diseases,genomic data to date have been accumulate...Rheumatic diseases differ in severity and outcome across ethnic groups.Although genetic predisposition is an important factor influencing the development of rheumatic diseases,genomic data to date have been accumulated mainly in Europeans.However,East Asia has become an influential center for genetic studies worldwide,and there is also a growing need for a functional genome database for East Asians.Expression quantitative trait locus data for immune cell subsets can be extremely useful in interpreting the function of disease-associated genetic polymorphisms.The development of a functional genome database for East Asians is expected to make a significant contribution to the understanding and stratification of the pathogenesis of rheumatic diseases in this population in the future.展开更多
基金Supported by National Institutes of Health(NIH/NIDDK),Nos.R01 DK090111 and DK039311
文摘Type 2 diabetes(T2D) is a common metabolic disorder which is caused by multiple genetic perturbations affecting different biological pathways. Identifying genetic factors modulating the susceptibility of this complex heterogeneous metabolic phenotype in different ethnic and racial groups remains challenging. Despite recent success, the functional role of the T2D susceptibility variants implicated by genome-wide association studies(GWAS) remains largely unknown. Genetic dissection of transcript abundance or expression quantitative trait(eQTL) analysis unravels the genomic architecture of regulatory variants. Availability of eQTL information from tissues relevant for glucose homeostasis in humans opens a new avenue to prioritize GWASimplicated variants that may be involved in triggering a causal chain of events leading to T2D. In this article, we review the progress made in the field of eQTL research and knowledge gained from those studies in understanding transcription regulatory mechanisms in human subjects. We highlight several novel approaches that can integrate eQTL analysis with multiple layers of biological information to identify ethnic-specific causal variants and gene-environment interactions relevant to T2D pathogenesis. Finally, we discuss how the eQTL analysis mediated search for "missing heritability" may lead us to novel biological and molecular mechanisms involved in susceptibility to T2D.
基金the Natural Science Foundation of China,Nos.81200828(to YC),32070998(to GC)the Key Research and Development Program(Social Development)of Jiangsu Province,No.BE2020667(to GC)+1 种基金the Foundation of Jiangsu Province"333 Project High-level Talents",No.BRA2020076(to GC)the Priority Academic Program Development of Jiangsu Higher Education Institutes(PAPD)。
文摘Alzheimer's disease(AD)is affected by genetic factors.Polymorphisms in the glutathione S-transfe rase omega-1(Gsto1)gene have been shown by genetic correlation analyses performed in different ethnic populations to be genetic risk factors for AD.Gene expression profile data from BXD recombinant inbred mice were used in combination with genetic and bioinformatic analyses to chara cterize the mechanisms underlying regulation of Gstol variation regulation and to identify network membe rs that may contribute to AD risk or progression.Allele-specific assays confirmed that variation in Gstol expression is controlled by cis-expression quantitative trait loci.We found that Gstol mRNA levels were related to several central nervous system traits,such as glial acidic fibrillary protein levels in the caudate putamen,co rtical gray matter volume,and hippocampus mossy fiber pathway volume.We identified 2168 genes whose expression was highly correlated with that of Gsto1.Some genes were enriched for the most common neurodegenerative diseases.Some Gsto1-related genes identified in this study had previously been identified as susceptibility genes for AD,such as APP,Grin2 b,Ide,and Psenen.To evaluate the relationships between Gstol and candidate network members,we transfected astrocytes with Gstol siRNA and assessed the effect on putative downstream effecto rs.We confirmed that knockdown of Gstol had a significant influence on Pa2g4 expression,suggesting that Pa2g4 may be a downstream effector of Gstol,and that both genes intera ct with other genes in a network during AD pathogenesis.
基金Funding XS was in receipt of a National Natural Science Foundation of China(NSFC)grant(No.12171495)a Natural Science Foundation of Guangdong Province grant(No.2114050001435)+3 种基金a National Key Research and Development Program grant(No.2022YFF1202105)Swedish Research Council(Vetenskapsraet)grants(No.2017-02543&No.2022-01309)supported by the Swedish Research Council grant(No.2017-02543)XS The Swedish National Infrastructure for Computing(SNIC)utilized was partially funded by the Swedish Research Council through grant agreement No.2018-05973.
文摘Alternative splicing exists in most multi-exonic genes,and exploring these complex alternative splicing events and their resultant isoform expressions is essential.However,it has become conventional that RNA sequencing results have often been summarized into gene-level expression counts mainly due to the multiple ambiguous mapping of reads at highly similar regions.Transcript-level quantification and interpretation are often overlooked,and biological interpretations are often deduced based on combined transcript information at the gene level.Here,for the most variable tissue of alternative splicing,the brain,we estimate isoform expressions in 1,191 samples collected by the Genotype-Tissue Expression(GTEx)Consortium using a powerful method that we previously developed.We perform genome-wide association scans on the isoform ratios per gene and identify isoform-ratio quantitative trait loci(irQTL),which could not be detected by studying gene-level expressions alone.By analyzing the genetic architecture of the irQTL,we show that isoform ratios regulate edu-cational attainment via multiple tissues including the frontal cortex(BA9),cortex,cervical spinal cord,and hippocampus.These tissues are also associated with different neuro-related traits,including Alzheimer’s or dementia,mood swings,sleep duration,alcohol intake,intelligence,anxiety or depression,etc.Mendelian randomization(MR)analysis revealed 1,139 pairs of isoforms and neuro-related traits with plausible causal relationships,showing much stronger causal effects than on general diseases measured in the UK Biobank(UKB).Our results highlight essential transcript-level biomarkers in the human brain for neuro-related complex traits and diseases,which could be missed by merely investigating overall gene expressions.
基金funded by The Ningde Science and Technology Plan Project of China(Grant No.20170013).
文摘Background and aim:A genome-wide association study has indicated the association of numerous genes in the 6p21.3 region with chronic hepatitis B virus(HBV)infection.In this study,we screened 12 representative single-nucleotide polymorphisms(SNPs)from the 6p21.3 region and investigated their association with the risk of chronic hepatitis B(CHB)to better understand the molecular etiology un-derlying CHB risk in the Han Chinese population.Methods:Between March 2021 and November 2022,we included 183 patients with CHB(case group)and 196 with natural HBV clearance(control group).Allele typing of the selected SNPs was performed using snapshot technology.The correlation between the 12 chosen SNPs and the risk of chronic HBV infection was examined using binary logistic regression analysis.Interacting genes of the variants were identified,and expression quantitative trait loci(eQTL)were analyzed using the 3DSNP database.Results:We validated 12 previously reported CHB susceptibility sites,including rs1419881 of tran-scription factor 19(TCF19),rs3130542 and rs2853953 of human leukocyte antigen(HLA)-C,rs652888 of euchromatic histone-lysine-methyltransferase 2(EHMT2),rs2856718,rs9276370,rs7756516,and rs7453920 of HLA-DQ,rs378352 of HLA-DOA,and rs3077,rs9277535,and rs9366816 of HLA-DP.Logistic regression analyses revealed that polymorphisms such as rs9276370,rs7756516,rs7453920,rs3077,rs9277535,and rs9366816 were positively correlated with natural HBV clearance in the dominant model.Conversely,rs3130542 and rs378352 were identified as risk factors for CHB.Haplotype analysis revealed that rs9276370,rs7756516,and rs7453920 in HLA-DQ were TTG and GCA haplotypes.Although the TTG haplotype was positively correlated with a higher risk of CHB,the GCA haplotype significantly influenced the natural clearance of HBV.Bioinformatics analysis demonstrated that rs378352,rs3077,and rs9366816 were located within enhancer states;rs3077 and rs9366816 overlapped with nine tran-scription factor-binding sites,whereas rs378352 altered five sequence motifs.Furthermore,eQTL analysis demonstrated the functional tendencies of eight statistically significant SNPs(rs3130542,rs9276370,rs7756516,rs7453920,rs378352,rs3077,rs9277535,and rs9366816).Conclusions:Genetic variations within the 6p21.3 region were associated with chronic HBV infection in the Han Chinese population in southern China.Furthermore,the GCA haplotype including rs9276370,rs7756516,and rs7453920 of HLA-DQ contributed significantly to natural HBV clearance,implying that multiple SNPs exert a cumulative allelic effect on HBV infection.
基金the National Natural Science Foundation of China (30671270)the Hi-Tech Research and Development (863) Program of China(2006AA10Z1E9 and 2006AA100101)
文摘Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） population of 168 lines, which was generated from the cross between two elite Chinese common wheat （Triticum aestivum L.） varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat （SSR） and 22 expressed sequence tag （EST）-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.
文摘Gene expression regulation plays an important role in controlling plant phenotypes and adaptation. Here, we report a comprehensive assessment of gene expression variation through the transcriptome analyses of a large maize-teosinte experimental population. Genome-wide mapping identified 25 660 expression quantitative trait loci （eQTL） for 17 311 genes, capturing an unprecedented range of expression variation. We found that local eQTL were more frequently mapped to adjacent genes, displaying a mode of expression piggybacking, which consequently created co-regulated gene clusters. Genes within the co-regulated gene clusters tend to have relevant functions and shared chromatin modifications. Distant eQTL formed 125 significant distant eQTL hotspots with their targets significantly enriched in specific functional cate- gories. By integrating different sources of information, we identified putative trans- regulators for a variety of metabolic pathways. We demonstrated that the bHLH transcription factor R1 and hexokinase HEX9 might act as crucial regulators for flavonoid biosynthesis and glycolysis, respectively. Moreover, we showed that domestication or improvement has significantly affected global gene expression, with many genes targeted by selection. Of particular interest, the Bx genes for benzoxazinoid biosynthesis may have undergone coordinated cis-regulatory divergence between maize and teosinte, and a transposon insertion that inactivates Bx12 was under strong selection as maize spread into temperate environments with a distinct herbivore community.
基金the Intramural Research Program(Grant No.1ZIACP010201)the Division of Cancer Epidemiology and Genetics Informatics Tool Challenge of NCI.
文摘Genome-wide association studies(GWAS)have identified thousands of genomic loci associated with complex diseases and traits,including cancer.The vast majority of common traitassociated variants identified via GWAS fall in non-coding regions of the genome,posing a challenge in elucidating the causal variants,genes,and mechanisms involved.Expression quantitative trait locus(eQTL)and other molecular QTL studies have been valuable resources in identifying candidate causal genes from GWAS loci through statistical colocalization methods.While QTL colocalization is becoming a standard analysis in post-GWAS investigation,an easy web tool for users to perform formal colocalization analyses with either user-provided or public GWAS and eQTL datasets has been lacking.Here,we present ezQTL,a web-based bioinformatic application to interactively visualize and analyze genetic association data such as GWAS loci and molecular QTLs under different linkage disequilibrium(LD)patterns(1000 Genomes Project,UK Biobank,or user-provided data).This application allows users to perform data quality control for variants matched between different datasets,LD visualization,and two-trait colocalization analyses using two state-of-the-art methodologies(eCAVIAR and HyPrColoc),including batch processing.ezQTL is a free and publicly available cross-platform web tool,which can be accessed online at https://analysistools.cancer.gov/ezqtl.
基金Japan Agency for Medical Research and Development(AMED),Grant/Award Number:JP20ek0410074。
文摘Rheumatic diseases differ in severity and outcome across ethnic groups.Although genetic predisposition is an important factor influencing the development of rheumatic diseases,genomic data to date have been accumulated mainly in Europeans.However,East Asia has become an influential center for genetic studies worldwide,and there is also a growing need for a functional genome database for East Asians.Expression quantitative trait locus data for immune cell subsets can be extremely useful in interpreting the function of disease-associated genetic polymorphisms.The development of a functional genome database for East Asians is expected to make a significant contribution to the understanding and stratification of the pathogenesis of rheumatic diseases in this population in the future.
