AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers...AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers, 66 chronic hepatitis (CH), 66 liver cirrhosis (LC) and 63 hepatocellular carcinoma (HCC) patients. Statistical significances were determined using Fisher's exact test, χ 2 test, and t -test analyses whenever appropriate. Pre-S mutation as a risk factor for advanced liver disease was estimated by unconditional logistic regression model adjusted with age, sex, and hepatitis B e antigen (HBeAg). P < 0.05 was considered significant. RESULTS: Mutation of the hepatitis B virus (HBV) pre-S2 start codon was found in 59 samples from 268 subjects (22.0%), with higher prevalence in patients with cirrhosis 27/66 (40.9%) followed by HCC 18/63 (28.6%), chronic hepatitis 12/66 (18.2%) and asymptomatic carriers 2/73 (2.7%) (P < 0.001). Logistic regression analysis showed that pre-S2 start codon mutation was an independent factor for progressive liver disease. Other mutations, at T130, Q132, and A138, were also associated with LC and HCC, although this was not statistically significant when adjusted for age, sex, and HBeAg. The prevalence of pre-S2 start codon mutation was higher in HBV/B than in HBV/C (23.0% vs 19.1%), whilst the prevalence of T130, Q132, and A138 mutation was higher in HBV/C than in HBV/B. The prevalence of pre-S2 start codon mutation was higher in LC (38.9%) and HCC (40.0%) than CH (5.6%) in HBeAg(+) group, but it was similar between CH, LC and HCC in HBeAg(-) group. CONCLUSION: Pre-S2 start codon mutation was higher in Indonesian patients compared to other Asian countries, and its prevalence was associated with advanced liver disease, particularly in HBeAg(+) patients.展开更多
The present study was designed to investigate the effects of start codon of nos M on the biosynthesis of nosiheptide. Target genes were amplified by overlap PCR. After homologous recombination to construct engineered ...The present study was designed to investigate the effects of start codon of nos M on the biosynthesis of nosiheptide. Target genes were amplified by overlap PCR. After homologous recombination to construct engineered strains, nosiheptide production was analyzed by HPLC. Three mutants with different start codon of nos M were constructed, and nosiheptide production of each mutant was analyzed and compared. Replacement of the start codon of nos M significantly decreased the production of nosiheptide. In conclusion, start codon usage could greatly affect the biosynthetic efficiency in the biosynthetic gene cluster of nosiheptide.展开更多
AIIopolyploidy has played an important role in plant evolution and heterosis. Recent studies indicate that the process of wide hybridization and （or） polyploidization may induce rapid and extensive genetic and epige...AIIopolyploidy has played an important role in plant evolution and heterosis. Recent studies indicate that the process of wide hybridization and （or） polyploidization may induce rapid and extensive genetic and epigenetic changes in some plant species. To better understand the allopolyploidy evolutionism and the genetic mechanism of Arachis interspecific hybridization, this study was conducted to monitor the gene expression variation by cDNA start codon targeted polymorphism （cDNA-SCoT） and cDNA high-frequency oligonucleotide-targeting active gene （cDNA-HFO-TAG） techniques, from the hybrids （F1） and newly synthesized allopolyploid generations （S0-$3） between tetraploid cultivated peanut Zhongkaihua 4 with diploid wild one Arachis doigoi. Rapid and considerable gene expression variations began as early as in the FI hybrid or immediately after chromosome doubling. Three types of gene expression changes were observed, including complete silence （gene from progenitors was not expressed in all progenies）, incomplete silence （gene expressed only in some progenies） and new genes activation. Those silent genes mainly involved in RNA transcription, metabolism, disease resistance, signal transduction and unknown functions. The activated genes with known function were almost retroelements by cDNA-SCoT technique and all metabolisms by cDNA-HFO-TAG. These findings indicated that interspecific hybridization and ploidy change affected gene expression via genetic and epigenetic alterations immediately upon allopolyploid formation, and some obtained transcripts derived fragments （TDFs） probably could be used in the research of molecular mechanism of Arachis allopolyploidization which contribute to thwe genetic diploidization of newly formed allopolyploids. Our research is valuable for understanding of peanut evolution and improving the utilization of putative and beneficial genes from the wild peanut.展开更多
The use of medicinal plants for different therapeutic values is well documented in African continent.African diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal va...The use of medicinal plants for different therapeutic values is well documented in African continent.African diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal value.The feasible conservation approach and sustainable harvesting for the medicinal species remains a huge challenge.However,conservation approach through different biotechnological tools such as micropropagation,somatic embryogenesis,synthetic seed production,hairy root culture,molecular markers based study and cryopreservation of endemic African medicinal species is much crucial.In this review,an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal species.The present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species.展开更多
基金Supported by MRIN Funding, Budget, No. cc041/2010
文摘AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers, 66 chronic hepatitis (CH), 66 liver cirrhosis (LC) and 63 hepatocellular carcinoma (HCC) patients. Statistical significances were determined using Fisher's exact test, χ 2 test, and t -test analyses whenever appropriate. Pre-S mutation as a risk factor for advanced liver disease was estimated by unconditional logistic regression model adjusted with age, sex, and hepatitis B e antigen (HBeAg). P < 0.05 was considered significant. RESULTS: Mutation of the hepatitis B virus (HBV) pre-S2 start codon was found in 59 samples from 268 subjects (22.0%), with higher prevalence in patients with cirrhosis 27/66 (40.9%) followed by HCC 18/63 (28.6%), chronic hepatitis 12/66 (18.2%) and asymptomatic carriers 2/73 (2.7%) (P < 0.001). Logistic regression analysis showed that pre-S2 start codon mutation was an independent factor for progressive liver disease. Other mutations, at T130, Q132, and A138, were also associated with LC and HCC, although this was not statistically significant when adjusted for age, sex, and HBeAg. The prevalence of pre-S2 start codon mutation was higher in HBV/B than in HBV/C (23.0% vs 19.1%), whilst the prevalence of T130, Q132, and A138 mutation was higher in HBV/C than in HBV/B. The prevalence of pre-S2 start codon mutation was higher in LC (38.9%) and HCC (40.0%) than CH (5.6%) in HBeAg(+) group, but it was similar between CH, LC and HCC in HBeAg(-) group. CONCLUSION: Pre-S2 start codon mutation was higher in Indonesian patients compared to other Asian countries, and its prevalence was associated with advanced liver disease, particularly in HBeAg(+) patients.
基金supported by the grants from the"111"Project from the Ministry of Education of China and State Administration of Foreign Export Affairs of China(No.111-2-07)the National Key Project on Science and Technology of China(No.2012ZX09103101-030&2012ZX09201101-012)+3 种基金National Science Foundation of China(No.81172967)the Doctoral Fund from the Ministry of Education of China(No.20110096110011)the Science&Technology Pillar Program of Jiangsu Province(No.SBE201371217)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The present study was designed to investigate the effects of start codon of nos M on the biosynthesis of nosiheptide. Target genes were amplified by overlap PCR. After homologous recombination to construct engineered strains, nosiheptide production was analyzed by HPLC. Three mutants with different start codon of nos M were constructed, and nosiheptide production of each mutant was analyzed and compared. Replacement of the start codon of nos M significantly decreased the production of nosiheptide. In conclusion, start codon usage could greatly affect the biosynthetic efficiency in the biosynthetic gene cluster of nosiheptide.
基金supported by the National Natural Science Foundation of China(No.21991132,No.52033010,and No.52021002)the National Key R&D Program of China(No.2020YFA0710700 and No.2020YFA0710703).
基金supported by the Guangxi Academy of Agricultural Sciences Foundation,China(2015JZ08 and 2015YT57)the Guangxi Sciences Foundation,China(2011GXNSFA018079)+1 种基金the Modern Agro-industry Technology Research System,China(CARS-14-19)the National Natural Science Foundation of China(31160294 and 31240059)
文摘AIIopolyploidy has played an important role in plant evolution and heterosis. Recent studies indicate that the process of wide hybridization and （or） polyploidization may induce rapid and extensive genetic and epigenetic changes in some plant species. To better understand the allopolyploidy evolutionism and the genetic mechanism of Arachis interspecific hybridization, this study was conducted to monitor the gene expression variation by cDNA start codon targeted polymorphism （cDNA-SCoT） and cDNA high-frequency oligonucleotide-targeting active gene （cDNA-HFO-TAG） techniques, from the hybrids （F1） and newly synthesized allopolyploid generations （S0-$3） between tetraploid cultivated peanut Zhongkaihua 4 with diploid wild one Arachis doigoi. Rapid and considerable gene expression variations began as early as in the FI hybrid or immediately after chromosome doubling. Three types of gene expression changes were observed, including complete silence （gene from progenitors was not expressed in all progenies）, incomplete silence （gene expressed only in some progenies） and new genes activation. Those silent genes mainly involved in RNA transcription, metabolism, disease resistance, signal transduction and unknown functions. The activated genes with known function were almost retroelements by cDNA-SCoT technique and all metabolisms by cDNA-HFO-TAG. These findings indicated that interspecific hybridization and ploidy change affected gene expression via genetic and epigenetic alterations immediately upon allopolyploid formation, and some obtained transcripts derived fragments （TDFs） probably could be used in the research of molecular mechanism of Arachis allopolyploidization which contribute to thwe genetic diploidization of newly formed allopolyploids. Our research is valuable for understanding of peanut evolution and improving the utilization of putative and beneficial genes from the wild peanut.
文摘The use of medicinal plants for different therapeutic values is well documented in African continent.African diverse biodiversity hotspots provide a wide range of endemic species,which ensures a potential medicinal value.The feasible conservation approach and sustainable harvesting for the medicinal species remains a huge challenge.However,conservation approach through different biotechnological tools such as micropropagation,somatic embryogenesis,synthetic seed production,hairy root culture,molecular markers based study and cryopreservation of endemic African medicinal species is much crucial.In this review,an attempt has been made to provide different in vitro biotechnological approaches for the conservation of African medicinal species.The present review will be helpful in further technology development and deciding the priorities at decision-making levels for in vitro conservation and sustainable use of African medicinal species.
