Mitochondrial DNA(mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system.This explains an increased mutation rate of mtDNA that results in heteroplasmy,e.g.,the co...Mitochondrial DNA(mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system.This explains an increased mutation rate of mtDNA that results in heteroplasmy,e.g.,the coexistence of the mutant and wild-type mtDNA molecules within the same mitochondrion.In diabetes mellitus,glycotoxicity,advanced oxidative stress,collagen cross-linking,and accumulation of lipid peroxides in foam macrophage cells and arterial wall cells may significantly decrease the mutation threshold required for mitochondrial dysfunction,which in turn further contributes to the oxidative damage of the diabetic vascular wall,endothelial dysfunc-tion,and atherosclerosis.展开更多
Rice(Oryza sativa L.)is an important staple food crop worldwide due to its adaptability to different environmental conditions.Because of its great economic and social importance,there is a constant requirement for new...Rice(Oryza sativa L.)is an important staple food crop worldwide due to its adaptability to different environmental conditions.Because of its great economic and social importance,there is a constant requirement for new varieties with improved agronomic characteristics,such as tolerance to different biotic(such as bacterium,fungus,insect and virus)and abiotic stresses(such as salinity,drought and temperature),higher yield and better organoleptic and nutritional value.Among the new genome editing technologies,the clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)(CRISPR/Cas)system allows precise and specific edition in a targeted genome region.It is one of the most frequently used techniques for the study of the function of new genes and for the development of mutant lines with enhanced tolerance to biotic and abiotic stresses,herbicide resistance or improved yield.The wide varieties of applications for this technology include simple non-homologous end joining,homologous recombination,gene replacement,and base editing.In this review,we analyzed how some of these applications have been used in rice cultivars to obtain rice varieties better adapted to current environmental conditions and market requirements.展开更多
Based on the thermal stress distribution for functionally gradient material (FGM) plates, a Genetic Algorithm (GA) method for the thermal stresses optimum design of FGM plate with computer technologies is given. The m...Based on the thermal stress distribution for functionally gradient material (FGM) plates, a Genetic Algorithm (GA) method for the thermal stresses optimum design of FGM plate with computer technologies is given. The minimum thermal stresses combination distribution for FGM is obtained.展开更多
Antibiotic-resistant bacteria severely threaten human health.Besides spontaneous mutations generated by endogenous factors,the resistance might also originate from mutations induced by certain antibiotics,such as the ...Antibiotic-resistant bacteria severely threaten human health.Besides spontaneous mutations generated by endogenous factors,the resistance might also originate from mutations induced by certain antibiotics,such as the fluoroquinolones.Such antibiotics increase the genome-wide mutation rate by introducing replication errors from the SOS response pathway or decreasing the efficiency of the DNA repair systems.However,the relative contributions of these molecular mechanisms remain unclear,hindering understanding of the generation of resistant pathogens.Here,using newly-accumulated mutations of wild-type and SOS-uninducible Escherichia coli strains,as well as those of the strains deficient for the mismatch repair(MMR)and the oxidative damage repair pathways,we find that the SOS response is the major mutagenesis contributor in mutation elevation,responsible for~30–50%of the total base-pair substitution(BPS)mutation-rate elevation upon treatment with sublethal levels of norfloxacin(0~50 ng/mL).We further estimate the significance of the effects on other mutational features of these mechanisms(i.e.,transversions,structural variations,and mutation spectrum)in E.coli using linear models.The SOS response plays a positive role in all three mutational features(mutation rates of BPSs,transversions,structural variations)and affects the mutational spectrum.The repair systems significantly reduce the BPS mutation rate and the transversion rate,regardless of whether antibiotics are present,while significantly increasing the structural variation rate in E.coli.Our results quantitatively disentangle the contributions of the SOS response and DNA repair systems in antibiotic-induced mutagenesis.展开更多
基金Supported by The Russian Ministry of Science and Education
文摘Mitochondrial DNA(mtDNA) is particularly prone to oxidation due to the lack of histones and a deficient mismatch repair system.This explains an increased mutation rate of mtDNA that results in heteroplasmy,e.g.,the coexistence of the mutant and wild-type mtDNA molecules within the same mitochondrion.In diabetes mellitus,glycotoxicity,advanced oxidative stress,collagen cross-linking,and accumulation of lipid peroxides in foam macrophage cells and arterial wall cells may significantly decrease the mutation threshold required for mitochondrial dysfunction,which in turn further contributes to the oxidative damage of the diabetic vascular wall,endothelial dysfunc-tion,and atherosclerosis.
文摘Rice(Oryza sativa L.)is an important staple food crop worldwide due to its adaptability to different environmental conditions.Because of its great economic and social importance,there is a constant requirement for new varieties with improved agronomic characteristics,such as tolerance to different biotic(such as bacterium,fungus,insect and virus)and abiotic stresses(such as salinity,drought and temperature),higher yield and better organoleptic and nutritional value.Among the new genome editing technologies,the clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein(Cas)(CRISPR/Cas)system allows precise and specific edition in a targeted genome region.It is one of the most frequently used techniques for the study of the function of new genes and for the development of mutant lines with enhanced tolerance to biotic and abiotic stresses,herbicide resistance or improved yield.The wide varieties of applications for this technology include simple non-homologous end joining,homologous recombination,gene replacement,and base editing.In this review,we analyzed how some of these applications have been used in rice cultivars to obtain rice varieties better adapted to current environmental conditions and market requirements.
文摘Based on the thermal stress distribution for functionally gradient material (FGM) plates, a Genetic Algorithm (GA) method for the thermal stresses optimum design of FGM plate with computer technologies is given. The minimum thermal stresses combination distribution for FGM is obtained.
基金supported by Laoshan Laboratory(LSKJ202203203)the National Natural Science Foundation of China(31961123002,32270435)+3 种基金the Fundamental Research Funds for the Central Universities(202161064)the Young Taishan Scholars Program of Shandong Province(tsqn201812024)the Natural Science Foundation of Shandong Province(ZR2023QC191)the National Institutes of Health award(R35-GM122566).
文摘Antibiotic-resistant bacteria severely threaten human health.Besides spontaneous mutations generated by endogenous factors,the resistance might also originate from mutations induced by certain antibiotics,such as the fluoroquinolones.Such antibiotics increase the genome-wide mutation rate by introducing replication errors from the SOS response pathway or decreasing the efficiency of the DNA repair systems.However,the relative contributions of these molecular mechanisms remain unclear,hindering understanding of the generation of resistant pathogens.Here,using newly-accumulated mutations of wild-type and SOS-uninducible Escherichia coli strains,as well as those of the strains deficient for the mismatch repair(MMR)and the oxidative damage repair pathways,we find that the SOS response is the major mutagenesis contributor in mutation elevation,responsible for~30–50%of the total base-pair substitution(BPS)mutation-rate elevation upon treatment with sublethal levels of norfloxacin(0~50 ng/mL).We further estimate the significance of the effects on other mutational features of these mechanisms(i.e.,transversions,structural variations,and mutation spectrum)in E.coli using linear models.The SOS response plays a positive role in all three mutational features(mutation rates of BPSs,transversions,structural variations)and affects the mutational spectrum.The repair systems significantly reduce the BPS mutation rate and the transversion rate,regardless of whether antibiotics are present,while significantly increasing the structural variation rate in E.coli.Our results quantitatively disentangle the contributions of the SOS response and DNA repair systems in antibiotic-induced mutagenesis.
