The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyl...The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.展开更多
The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetical...The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetically modified crops have played a crucial role in strengthening the foodsecurity worldwide. However, their usages in crop improvement have been highly limited due to multiplecaveats. Genome editing tools like transcriptional activator-like effector nucleases and clustered regularlyinterspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 (CRISPR/Cas9) haveeffectively overcome limitations of the conventional breeding methods and are being widely accepted forimprovement of crops. Among the genome editing tools, the CRISPR/Cas9 system has emerged as themost powerful tool of genome editing because of its efficiency, amicability, flexibility, low cost andadaptability. Accumulated evidences indicate that genome editing has great potential in improving thedisease resistance in crop plants. In this review, we offered a brief introduction to the mechanisms of differentgenome editing systems and then discussed recent developments in CRISPR/Cas9 system-based genomeediting towards enhancement of rice disease resistance by different strategies. This review also discussed thepossible applications of recently developed genome editing approaches like CRISPR/Cas12a (formerlyknown as Cpf1) and base editors for enhancement of rice disease resistance.展开更多
The CRISPR/Cas technology is emerging as a revolutionary genome editing tool in diverse organisms including plants,and has quickly evolved into a suite of versatile tools for sequence-specific gene manipulations beyon...The CRISPR/Cas technology is emerging as a revolutionary genome editing tool in diverse organisms including plants,and has quickly evolved into a suite of versatile tools for sequence-specific gene manipulations beyond genome editing.Here,we review the most recent applications of the CRISPR/Cas toolkit in plants and also discuss key factors for improving CRISPR/Cas performance and strategies for reducing the off-target effects.Novel technical breakthroughs in mammalian research regarding the CRISPR/Cas toolkit will also be incorporated into this review in hope to stimulate prospective users from the plant research community to fully explore the potential of these technologies.展开更多
About 250 to 350 million people worldwide are chronically infected with hepatitis B virus(HBV), and about 700000 patients per year die of HBV-related cirrhosis or hepatocellular carcinoma(HCC). Several anti-viral agen...About 250 to 350 million people worldwide are chronically infected with hepatitis B virus(HBV), and about 700000 patients per year die of HBV-related cirrhosis or hepatocellular carcinoma(HCC). Several anti-viral agents, such as interferon and nucleos(t)ide analogues(NAs), have been used to treat this disease. NAs especially have been shown to strongly suppress HBV replication, slowing the progression to cirrhosis and the development of HCC. However, reactivation of HBV replication often occurs after cessation of treatment, because NAs alone cannot completely remove covalentlyclosed circular DNA(ccc DNA), the template of HBV replication, from the nuclei of hepatocytes. Anti-HBV immune responses, in conjunction with interferon-γ and tumor necrosis factor-α, were found to eliminate ccc DNA, but complete eradication of ccc DNA by immune response alone is difficult, as shown in patients who recover from acute HBV infection but often show long-term persistence of small amounts of HBV-DNA in the blood. Several new drugs interfering with the life cycle of HBV in hepatocytes have been developed, with drugs targeting ccc DNA theoretically the most effective for radical cure of chronic HBV infection. However, the safety of these drugs should be extensively examined before application to patients, and combinations of several approaches may be necessary for radical cure of chronic HBV infection.展开更多
Bioinformatics is a usage of information technology to help solve biological problems by designing novel and incisive algorithms and methods of analyses.Bioinfonnatics becomes a discipline vital in the era of post-gen...Bioinformatics is a usage of information technology to help solve biological problems by designing novel and incisive algorithms and methods of analyses.Bioinfonnatics becomes a discipline vital in the era of post-genomics. In this review article,the application of bioinformatics in tropical medicine will be presented and discussed.展开更多
Background Primary ovarian insufficiency （POI） is defined as a primary ovarian defect characterized by absent menarche （primary amenorrhea） or premature depletion of ovarian follicles before the age of 40 years. T...Background Primary ovarian insufficiency （POI） is defined as a primary ovarian defect characterized by absent menarche （primary amenorrhea） or premature depletion of ovarian follicles before the age of 40 years. The etiology of primary ovarian insufficiency in human female patients is still unclear. The purpose of this study is to investigate the potential genetic causes in primary amenorrhea patients by high resolution array based comparative genomic hybridization （array-CGH） analysis. Methods Following the standard karyotyping analysis, genomic DNA from whole blood of 15 primary amenorrhea patients and 15 normal control women was hybridized with Affymetrix cytogenetic 2.7M arrays following the standard protocol. Copy number variations identified by array-CGH were confirmed by real time polymerase chain reaction.展开更多
基金supported by Recruitment program of Global Youth Expert of China (to X.G.)the Elite Youth Program of the Chinese Academy of Agricultural Science (to X.G.)the intramural research support from Biotechnology Research Institute, Chinese Academy of Agricultural Sciences
文摘The most common and abundant DNA modification is 5-methylcytosine（5mC）,which has been well-established as an epigenetic mark regulating gene expression in eukaryotes（Jones,2012）.Another DNA modification N^6-methyldeoxyadenosine（6mA）,previously reported as a widespread DNA methylation in prokaryotes.
基金the China Priority Program-Breeding of Seven Major Crops(Grant No.2017YFD01100100)the Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.01-ICS)the Talented Young Scientist Program of China(Grant No.India-17-01).
文摘The emerging pests and phytopathogens have reduced the crop yield and quality, which hasthreatened the global food security. Traditional breeding methods, molecular marker-based breedingapproaches and use of genetically modified crops have played a crucial role in strengthening the foodsecurity worldwide. However, their usages in crop improvement have been highly limited due to multiplecaveats. Genome editing tools like transcriptional activator-like effector nucleases and clustered regularlyinterspaced short palindromic repeats (CRISPR)-associated endonuclease Cas9 (CRISPR/Cas9) haveeffectively overcome limitations of the conventional breeding methods and are being widely accepted forimprovement of crops. Among the genome editing tools, the CRISPR/Cas9 system has emerged as themost powerful tool of genome editing because of its efficiency, amicability, flexibility, low cost andadaptability. Accumulated evidences indicate that genome editing has great potential in improving thedisease resistance in crop plants. In this review, we offered a brief introduction to the mechanisms of differentgenome editing systems and then discussed recent developments in CRISPR/Cas9 system-based genomeediting towards enhancement of rice disease resistance by different strategies. This review also discussed thepossible applications of recently developed genome editing approaches like CRISPR/Cas12a (formerlyknown as Cpf1) and base editors for enhancement of rice disease resistance.
基金supported by the National Natural Science Foundation of China(Grant Nos. 31522006 and 31570276)funds from Sun Yatsen University and from China's Thousand Young Talents Program to J.-F.Li
文摘The CRISPR/Cas technology is emerging as a revolutionary genome editing tool in diverse organisms including plants,and has quickly evolved into a suite of versatile tools for sequence-specific gene manipulations beyond genome editing.Here,we review the most recent applications of the CRISPR/Cas toolkit in plants and also discuss key factors for improving CRISPR/Cas performance and strategies for reducing the off-target effects.Novel technical breakthroughs in mammalian research regarding the CRISPR/Cas toolkit will also be incorporated into this review in hope to stimulate prospective users from the plant research community to fully explore the potential of these technologies.
文摘About 250 to 350 million people worldwide are chronically infected with hepatitis B virus(HBV), and about 700000 patients per year die of HBV-related cirrhosis or hepatocellular carcinoma(HCC). Several anti-viral agents, such as interferon and nucleos(t)ide analogues(NAs), have been used to treat this disease. NAs especially have been shown to strongly suppress HBV replication, slowing the progression to cirrhosis and the development of HCC. However, reactivation of HBV replication often occurs after cessation of treatment, because NAs alone cannot completely remove covalentlyclosed circular DNA(ccc DNA), the template of HBV replication, from the nuclei of hepatocytes. Anti-HBV immune responses, in conjunction with interferon-γ and tumor necrosis factor-α, were found to eliminate ccc DNA, but complete eradication of ccc DNA by immune response alone is difficult, as shown in patients who recover from acute HBV infection but often show long-term persistence of small amounts of HBV-DNA in the blood. Several new drugs interfering with the life cycle of HBV in hepatocytes have been developed, with drugs targeting ccc DNA theoretically the most effective for radical cure of chronic HBV infection. However, the safety of these drugs should be extensively examined before application to patients, and combinations of several approaches may be necessary for radical cure of chronic HBV infection.
文摘Bioinformatics is a usage of information technology to help solve biological problems by designing novel and incisive algorithms and methods of analyses.Bioinfonnatics becomes a discipline vital in the era of post-genomics. In this review article,the application of bioinformatics in tropical medicine will be presented and discussed.
文摘Background Primary ovarian insufficiency （POI） is defined as a primary ovarian defect characterized by absent menarche （primary amenorrhea） or premature depletion of ovarian follicles before the age of 40 years. The etiology of primary ovarian insufficiency in human female patients is still unclear. The purpose of this study is to investigate the potential genetic causes in primary amenorrhea patients by high resolution array based comparative genomic hybridization （array-CGH） analysis. Methods Following the standard karyotyping analysis, genomic DNA from whole blood of 15 primary amenorrhea patients and 15 normal control women was hybridized with Affymetrix cytogenetic 2.7M arrays following the standard protocol. Copy number variations identified by array-CGH were confirmed by real time polymerase chain reaction.
