Hepatitis B virus(HBV)affects approximately two billion people worldwide and more than 240 million people in the world are currently chronic carrier that could develop serious complications in the future,like liver ci...Hepatitis B virus(HBV)affects approximately two billion people worldwide and more than 240 million people in the world are currently chronic carrier that could develop serious complications in the future,like liver cirrhosis and hepatocellular carcinoma.Although an extended HBV immunization program is being carried out since the early‘80s,representing effective preventive measure,leading to a dramatic reduction of HBV hepatitis incidence,globally HBV infection still represents a major public health problem.The HBV virus is a DNA virus belongs to the Hepadnaviridae family.The HBV-DNA is a circular,partial double strand genome.All coding information is on the minus DNA strand and it is organized into four open reading frames.Despite hepatitis B virus is a DNA virus,it has a high mutation rate due to its replicative strategy,that leads to the production of many nonidentical variants at each cycle of replication.In fact,it contains a polymerase without the proofreading activity,and uses an RNA intermediate(pg RNA)during its replication,so error frequencies are comparable to those seen in retroviruses and other RNA viruses rather than in more stable DNA viruses.Due to the low fidelity of the polymerase,the high replication rate and the overlapping reading frames,mutations occur throughout the genome and they have been identified both in the structural and not structural gene.The arise of mutations being to develop of a whole of viral variants called"quasi-species"and the prevalent population,which favors virus replication,was selected by viral fitness,host’s immune pressure and external pressure,i.e.,vaccination or antiviral therapy.Naturally occurring mutations were found both in acute and chronic subjects.In the present review we examine and discuss the most recent available data about HBV genetic variability and its significance.展开更多
OBJECTIVE: To investigate the genotypes of hepatitis E viruses (HEV) detected in sera of patients from different regions of China. METHODS: The partial genome (nt6461-6860, nt5994-6294) of open reading frame 2 (ORF2) ...OBJECTIVE: To investigate the genotypes of hepatitis E viruses (HEV) detected in sera of patients from different regions of China. METHODS: The partial genome (nt6461-6860, nt5994-6294) of open reading frame 2 (ORF2) of 45 HEV strains detected from 14 cities of China was amplified and sequenced using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Forty-one of 45 strains (91%) share the same genotype with HEV Burma strain (B), with nucleotide identities higher than 98% with the representative HEV Chinese strain. Only 4 HEV strains are significantly divergent from the 3 prototype strains of HEV, with nucleotide identities of 77%-80% with HEV Burmese/Chinese strain, 74%-76% with Mexican strain and 74%-77% with the newly discovered HEV US/swine strain, respectively. Phylogenetic analysis suggests that these 4 strains may represent 2 different subtypes that belong to a novel genotype of HEV, which is significantly divergent from the prototype Mexico, Burmese and US/swine strains. CONCLUSION: Among patients with hepatitis E in China, most are infected by the Chinese prototype HEV, and only a small part by the new genotype HEV.展开更多
目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长...目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长曲线,流式细胞仪分析细胞周期,β-半乳糖苷酶染色检测细胞衰老情况,Western blotting检测转染细胞中L1-ORF2、P53、P21蛋白表达水平。结果成功构建了稳定的GES-1细胞衰老模型及L1-ORF2si RNA载体。与转染了阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的正常及衰老GES-1细胞的L1-ORF2表达均下降(P<0.05)。与转染阴性对照载体的衰老GES-1细胞相比,转染L1-ORF2 si RNA载体的衰老GES-1细胞增殖速度变快(P<0.05),G0/G1期比例明显减少(34.2%vs 39.3%,P<0.05),β-半乳糖苷酶染色比例下降(56%vs 69%,P<0.05),而转染阴性对照载体和L1-ORF2 si RNA载体的正常GES-1细胞相比则无明显差异(P>0.05)。P53蛋白仅在衰老GES-1细胞中有表达,在正常GES-1细胞中无表达,而P21蛋白在正常和衰老的GES-1细胞中均有表达,且后者表达更高(P<0.05)。与转染阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的GES-1细胞P53、P21蛋白表达量明显下降(P<0.05)。结论L1-ORF2 si RNA载体可使正常及衰老的GES-1细胞中L1-ORF2表达下调,促进衰老GES-1细胞的生长和增殖,而对正常GES-1细胞无明显影响。P53、P21蛋白参与了L1-ORF2调控细胞衰老的过程。展开更多
Background DNA analysis has shown a lack of significant compatibility between couples affected by unexplained recurrent spontaneous abortion (URSA) compared with normal fertile couples, 8 although one study that ma...Background DNA analysis has shown a lack of significant compatibility between couples affected by unexplained recurrent spontaneous abortion (URSA) compared with normal fertile couples, 8 although one study that made use of a PCR-sequence-specific oligonucleotide (SSO) method did observe evidence of significant compatibility in the HLA-DQA1 and DQB1 alleles between patients and aborted fetuses. 9 This study was designed to investigate whether URSA were associated with particular DQ alleles or promoter alleles.Methods Thirty-two patients with URSA and 54 women who had had at least one successful pregnancy were included in this study. HLA-DQ genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The HLA-DQB1 promoter was detected by the SSO and sequence-specific primer (SSP) methods. The DQA1, DQB1, and DQB1 promoter (QBP) gene frequencies in the patients were compared with the gene frequencies in normal controls. The data were analyzed statistically with the χ 2 and Fisher’s exact tests.Results The results showed that the frequency of DQB1 *0604/0605 was significantly higher and the frequency of DQB1 *0501/0502 was significantly lower in the patient group as compared with the normal controls. In addition, the frequencies of the DQA1 *01-DQB1 *0604/0605 and QBP6.2-DQB1 *0604/0605 haplotypes were overrepresented in the patients relative to the controls. Our results did not show any differences between URSA patients and the controls with regard to DQA1 and QBP allele frequencies. Conclusions Our data suggest that URSA is associated with the HLA-DQB1 coding region, and is not associated with its upstream regulatory region. The DQB1 *0604/0605, DQA1 *01-DQB1 *0604/0605, and QBP6.2-DQB1 *0604/0605 haplotypes may confer susceptibility to URSA, while the DQB1 *0501/0502 allele may protect women from URSA.展开更多
小开放阅读框(small open reading frame,sORF)广泛存在于不同生物基因组中,由于其序列短,以及编码的产物小蛋白(small protein,或称微蛋白;microprotein或迷你蛋白miniprotein)检测困难等原因,小开放阅读框长期未得到充分注释和研究。...小开放阅读框(small open reading frame,sORF)广泛存在于不同生物基因组中,由于其序列短,以及编码的产物小蛋白(small protein,或称微蛋白;microprotein或迷你蛋白miniprotein)检测困难等原因,小开放阅读框长期未得到充分注释和研究。近年来,随着高通量测序、翻译组和质谱分析等技术的不断发展,在不同生物中发现大量新的小开放阅读框,其编码的小蛋白及介导的翻译调控已应用于药物开发及植物抗病机理等研究。但是,目前对微生物的小开放阅读框相关研究和应用还相对有限。本文综述了小开放阅读框编码产物小蛋白的发现和鉴定,以及上游开放阅读框(upstream open reading frame,uORF)对mRNA翻译调控等最新研究进展,重点介绍了微生物基因组中小开放阅读框的鉴定和功能研究进展,为深入认识微生物中小开放阅读框的功能和作用机制,以及植物和动物等高等其他生物的小蛋白和翻译调控相关研究提供参考。展开更多
小开放阅读框(small open reading frame,sORF)一般指基因组中能够编码长度在100个氨基酸左右或以内短肽的开放阅读框。它们广泛存在于植物基因组,却因编码短肽而常被基因组注释忽视。随着翻译组学和蛋白质组学测序技术的发展,具有翻译...小开放阅读框(small open reading frame,sORF)一般指基因组中能够编码长度在100个氨基酸左右或以内短肽的开放阅读框。它们广泛存在于植物基因组,却因编码短肽而常被基因组注释忽视。随着翻译组学和蛋白质组学测序技术的发展,具有翻译活性的sORF被证实广泛存在于植物基因组,且参与植物生长发育等重要过程的调控。该文归纳了近些年来植物领域sORF的一些研究进展,主要包括sORF的来源与分类、信息学预测方法和生物学功能等,并基于此对植物sORF未来的研究方向进行了展望。展开更多
文摘Hepatitis B virus(HBV)affects approximately two billion people worldwide and more than 240 million people in the world are currently chronic carrier that could develop serious complications in the future,like liver cirrhosis and hepatocellular carcinoma.Although an extended HBV immunization program is being carried out since the early‘80s,representing effective preventive measure,leading to a dramatic reduction of HBV hepatitis incidence,globally HBV infection still represents a major public health problem.The HBV virus is a DNA virus belongs to the Hepadnaviridae family.The HBV-DNA is a circular,partial double strand genome.All coding information is on the minus DNA strand and it is organized into four open reading frames.Despite hepatitis B virus is a DNA virus,it has a high mutation rate due to its replicative strategy,that leads to the production of many nonidentical variants at each cycle of replication.In fact,it contains a polymerase without the proofreading activity,and uses an RNA intermediate(pg RNA)during its replication,so error frequencies are comparable to those seen in retroviruses and other RNA viruses rather than in more stable DNA viruses.Due to the low fidelity of the polymerase,the high replication rate and the overlapping reading frames,mutations occur throughout the genome and they have been identified both in the structural and not structural gene.The arise of mutations being to develop of a whole of viral variants called"quasi-species"and the prevalent population,which favors virus replication,was selected by viral fitness,host’s immune pressure and external pressure,i.e.,vaccination or antiviral therapy.Naturally occurring mutations were found both in acute and chronic subjects.In the present review we examine and discuss the most recent available data about HBV genetic variability and its significance.
基金supported in part by the National Major Projects of National Committee of Sciences and Technology ，People’s Republic of China (No．96-9 16-03-07)；China Medical Board， New York(No．93-582)．
文摘OBJECTIVE: To investigate the genotypes of hepatitis E viruses (HEV) detected in sera of patients from different regions of China. METHODS: The partial genome (nt6461-6860, nt5994-6294) of open reading frame 2 (ORF2) of 45 HEV strains detected from 14 cities of China was amplified and sequenced using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Forty-one of 45 strains (91%) share the same genotype with HEV Burma strain (B), with nucleotide identities higher than 98% with the representative HEV Chinese strain. Only 4 HEV strains are significantly divergent from the 3 prototype strains of HEV, with nucleotide identities of 77%-80% with HEV Burmese/Chinese strain, 74%-76% with Mexican strain and 74%-77% with the newly discovered HEV US/swine strain, respectively. Phylogenetic analysis suggests that these 4 strains may represent 2 different subtypes that belong to a novel genotype of HEV, which is significantly divergent from the prototype Mexico, Burmese and US/swine strains. CONCLUSION: Among patients with hepatitis E in China, most are infected by the Chinese prototype HEV, and only a small part by the new genotype HEV.
文摘目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长曲线,流式细胞仪分析细胞周期,β-半乳糖苷酶染色检测细胞衰老情况,Western blotting检测转染细胞中L1-ORF2、P53、P21蛋白表达水平。结果成功构建了稳定的GES-1细胞衰老模型及L1-ORF2si RNA载体。与转染了阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的正常及衰老GES-1细胞的L1-ORF2表达均下降(P<0.05)。与转染阴性对照载体的衰老GES-1细胞相比,转染L1-ORF2 si RNA载体的衰老GES-1细胞增殖速度变快(P<0.05),G0/G1期比例明显减少(34.2%vs 39.3%,P<0.05),β-半乳糖苷酶染色比例下降(56%vs 69%,P<0.05),而转染阴性对照载体和L1-ORF2 si RNA载体的正常GES-1细胞相比则无明显差异(P>0.05)。P53蛋白仅在衰老GES-1细胞中有表达,在正常GES-1细胞中无表达,而P21蛋白在正常和衰老的GES-1细胞中均有表达,且后者表达更高(P<0.05)。与转染阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的GES-1细胞P53、P21蛋白表达量明显下降(P<0.05)。结论L1-ORF2 si RNA载体可使正常及衰老的GES-1细胞中L1-ORF2表达下调,促进衰老GES-1细胞的生长和增殖,而对正常GES-1细胞无明显影响。P53、P21蛋白参与了L1-ORF2调控细胞衰老的过程。
基金ThisstudywassupportedbytheNationalNaturalScienceFoundationofChina (No 3 9870 775 )
文摘Background DNA analysis has shown a lack of significant compatibility between couples affected by unexplained recurrent spontaneous abortion (URSA) compared with normal fertile couples, 8 although one study that made use of a PCR-sequence-specific oligonucleotide (SSO) method did observe evidence of significant compatibility in the HLA-DQA1 and DQB1 alleles between patients and aborted fetuses. 9 This study was designed to investigate whether URSA were associated with particular DQ alleles or promoter alleles.Methods Thirty-two patients with URSA and 54 women who had had at least one successful pregnancy were included in this study. HLA-DQ genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The HLA-DQB1 promoter was detected by the SSO and sequence-specific primer (SSP) methods. The DQA1, DQB1, and DQB1 promoter (QBP) gene frequencies in the patients were compared with the gene frequencies in normal controls. The data were analyzed statistically with the χ 2 and Fisher’s exact tests.Results The results showed that the frequency of DQB1 *0604/0605 was significantly higher and the frequency of DQB1 *0501/0502 was significantly lower in the patient group as compared with the normal controls. In addition, the frequencies of the DQA1 *01-DQB1 *0604/0605 and QBP6.2-DQB1 *0604/0605 haplotypes were overrepresented in the patients relative to the controls. Our results did not show any differences between URSA patients and the controls with regard to DQA1 and QBP allele frequencies. Conclusions Our data suggest that URSA is associated with the HLA-DQB1 coding region, and is not associated with its upstream regulatory region. The DQB1 *0604/0605, DQA1 *01-DQB1 *0604/0605, and QBP6.2-DQB1 *0604/0605 haplotypes may confer susceptibility to URSA, while the DQB1 *0501/0502 allele may protect women from URSA.
文摘小开放阅读框(small open reading frame,sORF)广泛存在于不同生物基因组中,由于其序列短,以及编码的产物小蛋白(small protein,或称微蛋白;microprotein或迷你蛋白miniprotein)检测困难等原因,小开放阅读框长期未得到充分注释和研究。近年来,随着高通量测序、翻译组和质谱分析等技术的不断发展,在不同生物中发现大量新的小开放阅读框,其编码的小蛋白及介导的翻译调控已应用于药物开发及植物抗病机理等研究。但是,目前对微生物的小开放阅读框相关研究和应用还相对有限。本文综述了小开放阅读框编码产物小蛋白的发现和鉴定,以及上游开放阅读框(upstream open reading frame,uORF)对mRNA翻译调控等最新研究进展,重点介绍了微生物基因组中小开放阅读框的鉴定和功能研究进展,为深入认识微生物中小开放阅读框的功能和作用机制,以及植物和动物等高等其他生物的小蛋白和翻译调控相关研究提供参考。
文摘小开放阅读框(small open reading frame,sORF)一般指基因组中能够编码长度在100个氨基酸左右或以内短肽的开放阅读框。它们广泛存在于植物基因组,却因编码短肽而常被基因组注释忽视。随着翻译组学和蛋白质组学测序技术的发展,具有翻译活性的sORF被证实广泛存在于植物基因组,且参与植物生长发育等重要过程的调控。该文归纳了近些年来植物领域sORF的一些研究进展,主要包括sORF的来源与分类、信息学预测方法和生物学功能等,并基于此对植物sORF未来的研究方向进行了展望。
