BACKGROUND:7,12-dimethylbenzanthracene(DMBA)-induced pancreatic intraepithelial neoplasia(PanIN)and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic ...BACKGROUND:7,12-dimethylbenzanthracene(DMBA)-induced pancreatic intraepithelial neoplasia(PanIN)and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic cancer.However,this model has not been characterized genetically,and in particular,the major genetic alterations in the p16 gene are unknown.METHODS: Lesions of PanlN and pancreatic cancer were induced with DMBA implantation in 40 rats, and control pancreatic tissue was obtained from 10 age-matched rats without exposure to DMBA. Pancreatic tissue was harvested three months after DMBA implantation and DNA was extracted. Homozy- gous deletions and point mutations of the pl6 (exons 1 and 2) gene were detected by PCR amplification and direct sequencing. RESULTS: DMBA implantation in the 40 rats induced 26 Pan- INs and 9 carcinomas. The overall frequency of p 16 alterations in the pancreatic tissue of these rats was 42.86% (15/35), and the changes were point mutations, not homozygous deletions. p16 mutations were present in 30.77% (8/26) of the rats with PanIN and 77.78% (7/9) of the rats with carcinoma (P〈0.05). The increasing incidence of p16 alterations was detected in 20.00% (1/5) of PanIN-1, 28.57% (2/7) of PanIN-2 and 35.71% (5/14) of PanIN-3 lesions. CONCLUSION: Our findings indicated that p16 alteration is a common event in the carcinogenesis of this model and that the mutation pattern is analogous to that of human lesions.展开更多
Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibi...Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibility and milk performance.Methods Based on bovine PRNP gene sequence,two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed.The PCR amplification and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations.Moreover,based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study,the corrections between the two indel mutations and BSE susceptibility were tested,as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.Results In the analyzed Chinese Holstein population,the frequencies of two"del"alleles in 23 bp and 12 bp indel muations were more frequent.The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del.From the estimated r2and D’values,two indel polymorphisms were linked strongly in the Holstein population(D’=57.5%,r2=0.257).Compared with the BSE-affected cattle populations from the reported data,the significant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations(P<0.05 or P<0.01).Similarly,there were significant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle(P<0.05 or P<0.01).Moreover,association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population,but no significant differences were found(P>0.05).Conclusions These observations revealed that the influence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits,which layed the foundation for future selection of resistant animals,and for improving health conditions for dairy breeding against BSE in China.展开更多
Dear editor,I am Dr.Jie Peng,from the Department of Ophthalmology,Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,Shanghai,China.I write to present a case report of a novel in-frame del...Dear editor,I am Dr.Jie Peng,from the Department of Ophthalmology,Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,Shanghai,China.I write to present a case report of a novel in-frame deletion mutation c.17779del TAC of neurofibromatosis type 1 in a Chinese boy with bilateral blindness.Neurofibromatosis type 1(NF1;OMIM#162200),an autosomal dominant disease,is caused by mutations in the NF1gene.The incidence of this disease is around 1 in 3500展开更多
Superoxide dismutase 2(SOD2)-mediated gene therapy has significant protective effects against kanamycin-induced hearing loss and hair cell loss in the inner ear,but the underlying mechanisms are still unclear.Herein,a...Superoxide dismutase 2(SOD2)-mediated gene therapy has significant protective effects against kanamycin-induced hearing loss and hair cell loss in the inner ear,but the underlying mechanisms are still unclear.Herein,an in vivo aging model of mitochondrial DNA(mtDNA)4834 deletion mutation was established using D-galactose,and the effects of noise or kanamycin on inner ear injury was investigated.Rats subjected to mtDNA4834 mutation via D-galactose administration showed hearing loss characterized by the disruption of inner ear structure(abnormal cell morphology,hair cell lysis,and the absence of the organ of Corti),increased SOD2 promoter methylation,and an increase in the degree of apoptosis.Exposure to noise or kanamycin further contributed to the effects of D-galactose.SOD2 overexpression induced by viral injection accordingly counteracted the effects of noise and kanamycin and ameliorated the symptoms of hearing loss,suggesting the critical involvement of SOD2 in preventing deafness and hearing-related conditions.The PI3K and MAPK signaling pathways were also regulated by noise/kanamycin exposure and/or SOD2 overexpression,indicating that they may be involved in the therapeutic effect of SOD2 against age-related hearing loss.展开更多
Summary: Mutations in the parkin gene have recently been identified in familial and isolated patients with early-onset Parkinson disease (PD) and that subregions between exon 2 and 4 of the parkin gene are hot spots o...Summary: Mutations in the parkin gene have recently been identified in familial and isolated patients with early-onset Parkinson disease (PD) and that subregions between exon 2 and 4 of the parkin gene are hot spots of deletive mutations. To study the distribution of deletions in the parkin gene among variant subset patients with PD in China, and to explore the role of parkin gene in the pathogenesis of PD, 63 patients were divided into early onset and later onset groups. Exons 1-12 were amplified by PCR, templated by the genomic DNA of patients, and then the deletion distribution detected by agarose electrophoresis. Four patients were found to be carrier of exon deletions in 63 patients with PD. The location of the deletion was on exon 2 (1 case), exon 3 (2 cases) and exon 4 (1 case). All patients were belong to the group of early onset PD. The results showed that parkin gene deletion on exon 2, exon 3 and exon 4 found in Chinese population contributes partly to early onset PD.展开更多
Background Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disease characterized by a combination of development anomalies and a predisposition to tumour formation. Mutation of patched gene...Background Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disease characterized by a combination of development anomalies and a predisposition to tumour formation. Mutation of patched gene (PTCH), considered the molecular defect of NBCCS, in a Chinese NBCCS family was investigated in this study. Methods Genomic DNA was isolated from blood samples of all 12 members of this family. The mutated PTCH gene was screened by polymerase chain reaction amplification and direct sequencing. Results A new mutation of 3 bp (GAT deletion) was found in all seven affected members of this family. This mutation caused one aspartate deletion in the fourth transmembrane domain of the PTCH protein located within the sterol sensing domain (SSD). This deletion was not found in any unaffected members of this family nor in 200 control samples.Conclusions Our findings suggest that one 3-bp deletion in PTCH gene was the cause of nevoid basal cell carcinoma in a Chinese family through affecting the conformation and function of PTCH protein.展开更多
Background The congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type ...Background The congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type 2 congenital LQTS (LQT2) is caused by gene mutations in the human ether-a-go-go-related gene (HERG).Methods A Chinese family diagnosed with LQTS were screened for KCNQ1,HERG and SCN5A,using polymerase chain reaction (PCR),direct sequencing,and clong sequencing.We also investigated the mRNA expression of the HERG gene.Results We identified a novel i414fs+98X mutation in the HERG gene.The deletion mutation of 14-bp in the first transmembrane segment (S1) introduced premature termination codons (PTCs) at the end of exon 6.This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels.But only the proband was symptomatic.Conclusions We found that the mRNA level of the HERG gene was significantly lower in 1414fs+98X carriers than in noncarriers.We found a novel 1414fs+98X mutation.The mRNA level supports that NMD mechanism might regulate the novel mutation.展开更多
The type Ⅱ toxin-antitoxin genes are responsible for the phenotypic switch to a quasi-dormant state that enables cell survival under stresses,a similar function to heterocyst of cyanobacteria. In this paper,we partic...The type Ⅱ toxin-antitoxin genes are responsible for the phenotypic switch to a quasi-dormant state that enables cell survival under stresses,a similar function to heterocyst of cyanobacteria. In this paper,we particularly study the role of gene pair all3211-asl3212 under Spectinomycin stress to reveal how the type Ⅱ toxin-antitoxin involved in environmental stress responses. Bioinformatics prediction shows that toxin protein gene All3211 is homologous to Maz F,a member of maz EF family that encoding nucleases. We clone gene all3211-asl3212 into expression vectors to identify its molecular characteristics. Deletion mutant strains of all3211-asl3212 are selected in a tri-parental mating screen. Phenotype comparisons of mutant and wild type reveals no difference of single-deletion-mutants in pigment integrity,the sensitivity to antibiotics,and heterocyst formation. The results show that deletion mutation of single TAS gene pair all3211-asl3212 results in limited effects on the cellular growth of PCC 7120. Thus,we suggest that dosage compensating might be provided from redundant genes or bypass pathways to offset obvious phenotypic differences.展开更多
基金supported by a grant from the National Natural Science Foundation of China(30972903)
文摘BACKGROUND:7,12-dimethylbenzanthracene(DMBA)-induced pancreatic intraepithelial neoplasia(PanIN)and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic cancer.However,this model has not been characterized genetically,and in particular,the major genetic alterations in the p16 gene are unknown.METHODS: Lesions of PanlN and pancreatic cancer were induced with DMBA implantation in 40 rats, and control pancreatic tissue was obtained from 10 age-matched rats without exposure to DMBA. Pancreatic tissue was harvested three months after DMBA implantation and DNA was extracted. Homozy- gous deletions and point mutations of the pl6 (exons 1 and 2) gene were detected by PCR amplification and direct sequencing. RESULTS: DMBA implantation in the 40 rats induced 26 Pan- INs and 9 carcinomas. The overall frequency of p 16 alterations in the pancreatic tissue of these rats was 42.86% (15/35), and the changes were point mutations, not homozygous deletions. p16 mutations were present in 30.77% (8/26) of the rats with PanIN and 77.78% (7/9) of the rats with carcinoma (P〈0.05). The increasing incidence of p16 alterations was detected in 20.00% (1/5) of PanIN-1, 28.57% (2/7) of PanIN-2 and 35.71% (5/14) of PanIN-3 lesions. CONCLUSION: Our findings indicated that p16 alteration is a common event in the carcinogenesis of this model and that the mutation pattern is analogous to that of human lesions.
基金supported by the National Natural Science Foundation of China (Grant No. 31272408 30972080)+2 种基金the National 863 Program of China (Grant No. 2013AA102505)the Program of National Beef Cattle and yak Industrial Technology System (CARS-38)the Agricultural Science and Technology Innovation Projects of Shanxi Province (No. 2012NKC01-13).
文摘Objective To investigate the 23 bp and 12 bp insertion/deletion(indel)mutations within the bovine prion protein(PRNP)gene in Chinese dairy cows,and to detect the associations of two indel mutations with BSE susceptibility and milk performance.Methods Based on bovine PRNP gene sequence,two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed.The PCR amplification and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations.Moreover,based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study,the corrections between the two indel mutations and BSE susceptibility were tested,as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.Results In the analyzed Chinese Holstein population,the frequencies of two"del"alleles in 23 bp and 12 bp indel muations were more frequent.The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del.From the estimated r2and D’values,two indel polymorphisms were linked strongly in the Holstein population(D’=57.5%,r2=0.257).Compared with the BSE-affected cattle populations from the reported data,the significant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations(P<0.05 or P<0.01).Similarly,there were significant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle(P<0.05 or P<0.01).Moreover,association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population,but no significant differences were found(P>0.05).Conclusions These observations revealed that the influence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits,which layed the foundation for future selection of resistant animals,and for improving health conditions for dairy breeding against BSE in China.
文摘Dear editor,I am Dr.Jie Peng,from the Department of Ophthalmology,Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine,Shanghai,China.I write to present a case report of a novel in-frame deletion mutation c.17779del TAC of neurofibromatosis type 1 in a Chinese boy with bilateral blindness.Neurofibromatosis type 1(NF1;OMIM#162200),an autosomal dominant disease,is caused by mutations in the NF1gene.The incidence of this disease is around 1 in 3500
基金Hubei Provincial Natural Science Foundation of China(No.2014CKB511).
文摘Superoxide dismutase 2(SOD2)-mediated gene therapy has significant protective effects against kanamycin-induced hearing loss and hair cell loss in the inner ear,but the underlying mechanisms are still unclear.Herein,an in vivo aging model of mitochondrial DNA(mtDNA)4834 deletion mutation was established using D-galactose,and the effects of noise or kanamycin on inner ear injury was investigated.Rats subjected to mtDNA4834 mutation via D-galactose administration showed hearing loss characterized by the disruption of inner ear structure(abnormal cell morphology,hair cell lysis,and the absence of the organ of Corti),increased SOD2 promoter methylation,and an increase in the degree of apoptosis.Exposure to noise or kanamycin further contributed to the effects of D-galactose.SOD2 overexpression induced by viral injection accordingly counteracted the effects of noise and kanamycin and ameliorated the symptoms of hearing loss,suggesting the critical involvement of SOD2 in preventing deafness and hearing-related conditions.The PI3K and MAPK signaling pathways were also regulated by noise/kanamycin exposure and/or SOD2 overexpression,indicating that they may be involved in the therapeutic effect of SOD2 against age-related hearing loss.
文摘Summary: Mutations in the parkin gene have recently been identified in familial and isolated patients with early-onset Parkinson disease (PD) and that subregions between exon 2 and 4 of the parkin gene are hot spots of deletive mutations. To study the distribution of deletions in the parkin gene among variant subset patients with PD in China, and to explore the role of parkin gene in the pathogenesis of PD, 63 patients were divided into early onset and later onset groups. Exons 1-12 were amplified by PCR, templated by the genomic DNA of patients, and then the deletion distribution detected by agarose electrophoresis. Four patients were found to be carrier of exon deletions in 63 patients with PD. The location of the deletion was on exon 2 (1 case), exon 3 (2 cases) and exon 4 (1 case). All patients were belong to the group of early onset PD. The results showed that parkin gene deletion on exon 2, exon 3 and exon 4 found in Chinese population contributes partly to early onset PD.
基金This work was supported by Key Project of National Natural Science Foundation of China (No. 30330580) and Shanghai Leading Academic Discipline Project (No. Y0203). Acknowledgements: Thanks to all the members of this Chinese family who participated in this study. Thanks for the support of the Chinese National Human Genome Centre at Shanghai. China.
文摘Background Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disease characterized by a combination of development anomalies and a predisposition to tumour formation. Mutation of patched gene (PTCH), considered the molecular defect of NBCCS, in a Chinese NBCCS family was investigated in this study. Methods Genomic DNA was isolated from blood samples of all 12 members of this family. The mutated PTCH gene was screened by polymerase chain reaction amplification and direct sequencing. Results A new mutation of 3 bp (GAT deletion) was found in all seven affected members of this family. This mutation caused one aspartate deletion in the fourth transmembrane domain of the PTCH protein located within the sterol sensing domain (SSD). This deletion was not found in any unaffected members of this family nor in 200 control samples.Conclusions Our findings suggest that one 3-bp deletion in PTCH gene was the cause of nevoid basal cell carcinoma in a Chinese family through affecting the conformation and function of PTCH protein.
文摘Background The congenital Long QT syndrome (LQTS) is a hereditary cardiac channelopathy that is characterized by a prolonged QT interval,syncope,ventricular arrhythmias,and sudden death.The chromosome 7-linked type 2 congenital LQTS (LQT2) is caused by gene mutations in the human ether-a-go-go-related gene (HERG).Methods A Chinese family diagnosed with LQTS were screened for KCNQ1,HERG and SCN5A,using polymerase chain reaction (PCR),direct sequencing,and clong sequencing.We also investigated the mRNA expression of the HERG gene.Results We identified a novel i414fs+98X mutation in the HERG gene.The deletion mutation of 14-bp in the first transmembrane segment (S1) introduced premature termination codons (PTCs) at the end of exon 6.This mutation would result in a serious phenotype if the truncated proteins co-assembled with normal subunit to form the defective channels.But only the proband was symptomatic.Conclusions We found that the mRNA level of the HERG gene was significantly lower in 1414fs+98X carriers than in noncarriers.We found a novel 1414fs+98X mutation.The mRNA level supports that NMD mechanism might regulate the novel mutation.
基金Supported by the National Natural Science Foundation of China(31001099/C190101)Central University Natural Science Foundation of China(CJSl3003,CJS13004)Key Laboratory of Microbiology and Biotrans Formation Funded Projects of South-Central University for Nationalities(XJS09002)
文摘The type Ⅱ toxin-antitoxin genes are responsible for the phenotypic switch to a quasi-dormant state that enables cell survival under stresses,a similar function to heterocyst of cyanobacteria. In this paper,we particularly study the role of gene pair all3211-asl3212 under Spectinomycin stress to reveal how the type Ⅱ toxin-antitoxin involved in environmental stress responses. Bioinformatics prediction shows that toxin protein gene All3211 is homologous to Maz F,a member of maz EF family that encoding nucleases. We clone gene all3211-asl3212 into expression vectors to identify its molecular characteristics. Deletion mutant strains of all3211-asl3212 are selected in a tri-parental mating screen. Phenotype comparisons of mutant and wild type reveals no difference of single-deletion-mutants in pigment integrity,the sensitivity to antibiotics,and heterocyst formation. The results show that deletion mutation of single TAS gene pair all3211-asl3212 results in limited effects on the cellular growth of PCC 7120. Thus,we suggest that dosage compensating might be provided from redundant genes or bypass pathways to offset obvious phenotypic differences.