We report here the characterization of a five-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON). Strik- ingly, this Chinese family displayed high penetrance and expressivity of visual lo...We report here the characterization of a five-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON). Strik- ingly, this Chinese family displayed high penetrance and expressivity of visual loss. The average age-of-onset of vision loss was 18 years in this family. Nineteen (11 males/8 females) of 29 matrilineal relatives in this family developed visual loss with a wide range of severity, ranging from blindness to normal vision. Sequence analysis of mitochondrial genome in this pedigree revealed the presence of the ND4 G 11778A mutation and 44 other variants belonging to Asian haplogroup M7b. The G 11778A mutation is present at homoplasmy in matri- lineal relatives of this Chinese family. Of other variants, the C01 G6480A, ND5 T12811C and Cytb A15395G located at highly conserved residues of corresponding polypeptides. In fact, these variants were implicated to be involved in other clinical abnormalities. Here, these variants may act in synergy with the primary LHON-associated Gl1778A mutation. Thus, the mitochondrial dysfunction caused by the primary ND4 G11778A mutation may be worsened by these mitochondrial variants. The results imply that the G6480A, T12811C and A15395G variants might have a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.展开更多
Intensively developed in the last few years, single-cell sequencing technologies now present numerous advantages over traditional sequencing methods for solving the problems of biological heterogeneity and low quantit...Intensively developed in the last few years, single-cell sequencing technologies now present numerous advantages over traditional sequencing methods for solving the problems of biological heterogeneity and low quantities of available biological materials. The application of single-cell sequencing technologies has profoundly changed our understanding of a series of biological phenomena, including gene transcription, embryo development, and carcinogenesis. However, before single-cell sequencing technologies can be used extensively, researchers face the serious challenge of overcoming inherent issues of high amplification bias, low accuracy and repro- ducibility. Here, we simply summarize the techniques used for single-cell isolation, and review the current technologies used in single-cell genomic, transcriptomic, and epigenomic sequencing, We discuss the merits, defects, and scope of application of single-cell sequencing technologies and then speculate on the direction of future developments.展开更多
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with considerable clinical and genetic heterogeneity.In this study,we identified all classes of genomic variants from whole-genome sequencing (WGS) datas...Autism spectrum disorder (ASD) is a neurodevelopmental disorder with considerable clinical and genetic heterogeneity.In this study,we identified all classes of genomic variants from whole-genome sequencing (WGS) dataset of 32 Chinese trios with ASD,including de novo mutations,inherited variants,copy number variants (CNVs) and genomic structural variants.A higher mutation rate (Poisson test,P<2.2×10) in exonic (1.37×10) and 3’-UTR regions (1.42×10) was revealed in comparison with that of whole genome (1.05×10).Using an integrated model,we identified 87 potentially risk genes (P<0.01) from 4832 genes harboring various rare deleterious variants,including CHD8 and NRXN2,implying that the disorders may be in favor to multiple-hit.In particular,frequent rare inherited mutations of several microcephaly-associated genes (ASPM,WDR62,and ZNF335)were found in ASD.In chromosomal structure analyses,we found four de novo CNVs and one de novo chromosomal rearrangement event,including a de novo duplication of UBE3A-containing region at 15q11.2-q13.1,which causes Angelman syndrome and microcephaly,and a disrupted TNR due to de novo chromosomal translocation t (1;5) (q25.1;q33.2).Taken together,our results suggest that abnormalities of centrosomal function and chromatin remodeling of the microcephaly-associated genes may be implicated in pathogenesis of ASD.Adoption of WGS as a new yet efficient technique to illustrate the full genetic spectrum in complex disorders,such as ASD,could provide novel insights into pathogenesis,diagnosis and treatment.展开更多
Organisms and cells,in response to environmental influences or during development,undergo considerable changes in DNA methylation on a genome-wide scale,which are linked to a variety of biological processes.Using Meth...Organisms and cells,in response to environmental influences or during development,undergo considerable changes in DNA methylation on a genome-wide scale,which are linked to a variety of biological processes.Using MethylC-seq to decipher DNA methylome at single-base resolution is prohibitively costly.In this study,we develop a novel approach,named MBRidge,to detect the methylation levels of repertoire CpGs,by innovatively introducing C-hydroxylmethylated adapters and bisulfate treatment into the MeDIP-seq protocol and employing ridge regression in data analysis.A systematic evaluation of DNA methylome in a human ovarian cell line T29 showed that MBRidge achieved high correlation(R>0.90)with much less cost(∼10%)in comparison with MethylC-seq.We further applied MBRidge to profiling DNA methylome in T29H,an oncogenic counterpart of T29’s.By comparing methylomes of T29H and T29,we identified 131790 differential methylation regions(DMRs),which are mainly enriched in carcinogenesis-related pathways.These are substantially different from7567 DMRs that were obtained by RRBS and related with cell development or differentiation.The integrated analysis ofDMRsin the promoterand expression of DMR-corresponding genes revealed thatDNAmethylation enforced reverse regulation of gene expression,depending on the distance fromthe proximalDMRto transcription starting sites in both mRNA and lncRNA.Taken together,our results demonstrate that MBRidge is an efficient and cost-effective method that can be widely applied to profiling DNA methylomes.展开更多
基金Zhejiang Provincial Natural Science Foundation(ZB0202);Chinese Young Scholar Award(No.30628013);the National Science Foundation of China to M.X.G and the Key Research and Development Program from Zhejiang Province(No.2004C14005)to J.Q.
文摘We report here the characterization of a five-generation Han Chinese family with Leber's hereditary optic neuropathy (LHON). Strik- ingly, this Chinese family displayed high penetrance and expressivity of visual loss. The average age-of-onset of vision loss was 18 years in this family. Nineteen (11 males/8 females) of 29 matrilineal relatives in this family developed visual loss with a wide range of severity, ranging from blindness to normal vision. Sequence analysis of mitochondrial genome in this pedigree revealed the presence of the ND4 G 11778A mutation and 44 other variants belonging to Asian haplogroup M7b. The G 11778A mutation is present at homoplasmy in matri- lineal relatives of this Chinese family. Of other variants, the C01 G6480A, ND5 T12811C and Cytb A15395G located at highly conserved residues of corresponding polypeptides. In fact, these variants were implicated to be involved in other clinical abnormalities. Here, these variants may act in synergy with the primary LHON-associated Gl1778A mutation. Thus, the mitochondrial dysfunction caused by the primary ND4 G11778A mutation may be worsened by these mitochondrial variants. The results imply that the G6480A, T12811C and A15395G variants might have a potential modifier role in increasing the penetrance and expressivity of the primary LHON-associated G11778A mutation in this Chinese family.
基金supported by the fund from the National High Technology Research and Development Program of China to Z.Sun (No.2012AA02A202)
文摘Intensively developed in the last few years, single-cell sequencing technologies now present numerous advantages over traditional sequencing methods for solving the problems of biological heterogeneity and low quantities of available biological materials. The application of single-cell sequencing technologies has profoundly changed our understanding of a series of biological phenomena, including gene transcription, embryo development, and carcinogenesis. However, before single-cell sequencing technologies can be used extensively, researchers face the serious challenge of overcoming inherent issues of high amplification bias, low accuracy and repro- ducibility. Here, we simply summarize the techniques used for single-cell isolation, and review the current technologies used in single-cell genomic, transcriptomic, and epigenomic sequencing, We discuss the merits, defects, and scope of application of single-cell sequencing technologies and then speculate on the direction of future developments.
基金supported by the grants from the Major State Basic Research Development Program of China(2012CB517902 and 2012CB517904)National Key Technology Research and Development Program of China(2012BAI03B00)+3 种基金Special Research Program of National Health and Family Planning Commission of China(201302002)International S&T Cooperation Program of China(2011DFA30670)National Natural Science Foundation of China(31571357/31771404)supported in part by research funding from AstraZeneca Innovation Center China and Wenzhou Medical University
文摘Autism spectrum disorder (ASD) is a neurodevelopmental disorder with considerable clinical and genetic heterogeneity.In this study,we identified all classes of genomic variants from whole-genome sequencing (WGS) dataset of 32 Chinese trios with ASD,including de novo mutations,inherited variants,copy number variants (CNVs) and genomic structural variants.A higher mutation rate (Poisson test,P<2.2×10) in exonic (1.37×10) and 3’-UTR regions (1.42×10) was revealed in comparison with that of whole genome (1.05×10).Using an integrated model,we identified 87 potentially risk genes (P<0.01) from 4832 genes harboring various rare deleterious variants,including CHD8 and NRXN2,implying that the disorders may be in favor to multiple-hit.In particular,frequent rare inherited mutations of several microcephaly-associated genes (ASPM,WDR62,and ZNF335)were found in ASD.In chromosomal structure analyses,we found four de novo CNVs and one de novo chromosomal rearrangement event,including a de novo duplication of UBE3A-containing region at 15q11.2-q13.1,which causes Angelman syndrome and microcephaly,and a disrupted TNR due to de novo chromosomal translocation t (1;5) (q25.1;q33.2).Taken together,our results suggest that abnormalities of centrosomal function and chromatin remodeling of the microcephaly-associated genes may be implicated in pathogenesis of ASD.Adoption of WGS as a new yet efficient technique to illustrate the full genetic spectrum in complex disorders,such as ASD,could provide novel insights into pathogenesis,diagnosis and treatment.
基金supported by grants from the NationalHigh Technology Research and Development Program of China(2012AA02A201,2012AA02A202)China-Canada Collaboration Project from the Ministry of Science and Technology of China(2011DFA30670)+1 种基金the National Natural Science Foundation of China(31171236/C060503)the Astra Zeneca Innovation Centre China.
文摘Organisms and cells,in response to environmental influences or during development,undergo considerable changes in DNA methylation on a genome-wide scale,which are linked to a variety of biological processes.Using MethylC-seq to decipher DNA methylome at single-base resolution is prohibitively costly.In this study,we develop a novel approach,named MBRidge,to detect the methylation levels of repertoire CpGs,by innovatively introducing C-hydroxylmethylated adapters and bisulfate treatment into the MeDIP-seq protocol and employing ridge regression in data analysis.A systematic evaluation of DNA methylome in a human ovarian cell line T29 showed that MBRidge achieved high correlation(R>0.90)with much less cost(∼10%)in comparison with MethylC-seq.We further applied MBRidge to profiling DNA methylome in T29H,an oncogenic counterpart of T29’s.By comparing methylomes of T29H and T29,we identified 131790 differential methylation regions(DMRs),which are mainly enriched in carcinogenesis-related pathways.These are substantially different from7567 DMRs that were obtained by RRBS and related with cell development or differentiation.The integrated analysis ofDMRsin the promoterand expression of DMR-corresponding genes revealed thatDNAmethylation enforced reverse regulation of gene expression,depending on the distance fromthe proximalDMRto transcription starting sites in both mRNA and lncRNA.Taken together,our results demonstrate that MBRidge is an efficient and cost-effective method that can be widely applied to profiling DNA methylomes.