Nature Structural and Molecular Biology于2015年11月9日在线发表了中国科学院上海生命科学研究院生物化学与细胞生物学研究所国家蛋白质科学中心（上海）雷鸣研究组的最新研究成果,揭示了端粒酶组分p75-p45-p19构成了四膜虫中独特的...Nature Structural and Molecular Biology于2015年11月9日在线发表了中国科学院上海生命科学研究院生物化学与细胞生物学研究所国家蛋白质科学中心（上海）雷鸣研究组的最新研究成果,揭示了端粒酶组分p75-p45-p19构成了四膜虫中独特的CST复合物。展开更多
The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicate...The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicated that no significant differences in the activity of ATPase and the micro- viscosity of plasma membrane of ultradried (UD) seeds could be found as compared to the control seeds stored under -20 degreesC, although there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of UD seeds. This implied that ultradry seed storage could protect the integrity of the membrane, maintain its physiological function and improve the storability of seeds. The relationship between sugar and desiccation tolerance of UD seeds was analysed using the HPLC. The results showed that the ratio of reducing to nonreducing sugar was lower in UD seeds than that in control. The content of sucrose and stachyose in elm and Chinese cabbage UD seeds was related to their desiccation tolerance, while no stachyose was detected in corn (Zea mays L.) seeds. This could be one of the reasons for its sensitivity to desiccation.展开更多
[Objective] This study aimed to analyze tyrosinase activity and its expression in Varicorhinus macrolepis. [Method] V. macrolepis was used as experimental material for the analysis and research of tyrosinase in nine k...[Objective] This study aimed to analyze tyrosinase activity and its expression in Varicorhinus macrolepis. [Method] V. macrolepis was used as experimental material for the analysis and research of tyrosinase in nine kinds of organs and tissues of male and female V. macrolepis individuals by using polyacrylamide gel electrophoresis and biochemical staining method, spectrophotometry and enzyme histochemical technology. [Result] Tyrosinase exists in the liver and pancreas, intestine and spleen of female and male V. macrolepis and in the gallbladder of male V. macrolepis. Tyrosinase activities in various tissues of V. macrolepis varied largely. Specifically, tyrosinase activities in the spleen was the maximum, which was higher in female V. macrolepis than in males. According to the enzyme histochemistry results, strong positive signals of tyrosinase existed in the spleen, intestine, liver and pancreas and gallbladder of V. macrolepis, which was the strongest in the spleen. [Conclusion] In this paper, research on tissue localization of tyrosinase in V. macrolepis had been first reported, which provided theoretical basis for further exploring the functions of tyrosinase in V. macrolepis.展开更多
AIM:To evaluate the value of ABC(D) stratification [combination of serum pepsinogen and Helicobacter pylori(H.pylori) antibody]of patients with gastric cancer.METHODS:Ninety-five consecutive patients with gastric canc...AIM:To evaluate the value of ABC(D) stratification [combination of serum pepsinogen and Helicobacter pylori(H.pylori) antibody]of patients with gastric cancer.METHODS:Ninety-five consecutive patients with gastric cancer were enrolled into the study.The serum pepsinogenⅠ(PGⅠ) /pepsinogenⅡ(PGⅡ) and H.pylori antibody levels were measured.Patients were classified into five groups of ABC(D) stratification according to their serological status.Endoscopic findings of atrophic gastritis and histological differentiation were also analyzed in relation to the ABC(D) stratification.RESULTS:The mean patient age was(67.9±8.9) years.Three patients(3.2%) were classified into group A,7 patients(7.4%) into group A',27 patients(28.4%) into group B,54 patients(56.8%) into group C,and 4patients(4.2%) into group D,respectively.There were only three cases in group A when the patients taking acid proton pump inhibitors and those who had undergone eradication therapy for H.pylori(group A') were excluded.These three cases had mucosal atrophy in the grey zone according to the diagnostic manual of ABC(D) stratification.Histologically,the mean age of the patients with well differentiated adenocarcinoma was significantly higher than that of the patients with poorly differentiated adenocarcinoma(P<0.05) .There were no differences in the pattern of atrophy in the endoscopies between the well differentiated and poorly differentiated groups.CONCLUSION:ABC(D) stratification is a good method for screening patients with gastric cancers.Endoscopy is needed for grey zone cases to check the extent of mucosal atrophy.展开更多
DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankt...DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankton communities. With the help of the available zooplankton databases, the zooplankton community of the Changjiang （Yangtze） River estuary was studied using a single-gene-targeted metagenomic method to estimate the species richness of this community. A total of 856 mitocbondrial cytochrome oxidase subunit 1 （coxl） gene sequences were determined. The environmental barcodes were clustered into 70 molecular operational taxonomic units （MOTUs）. Forty-two MOTUs matched barcoded marine organisms with more than 90% similarity and were assigned to either the species （similarity〉96%） or genus level （similarity〈96%）. Sibling species could also be distinguished. Many species that were overlooked by morphological methods were identified by molecular methods, especially gelatinous zooplankton and merozooplankton that were likely sampled at different life history phases. Zooplankton community structures differed significantly among all of the samples. The MOTU spatial distributions were influenced by the ecological habits of the corresponding species. In conclusion, single-gene-targeted metagenomic analysis is a useful tool for zooplankton studies, with which specimens from all life history stages can be identified quickly and effectively with a comprehensive database.展开更多
The fatty acid desaturase 2(fad2) gene was proven to be a major locus for high oleic acid(C18:1).Brassica napus is an amphidiploid species originating from a spontaneous hybridization of Brassica rapa and Brassica ole...The fatty acid desaturase 2(fad2) gene was proven to be a major locus for high oleic acid(C18:1).Brassica napus is an amphidiploid species originating from a spontaneous hybridization of Brassica rapa and Brassica oleracea.B.napus contains multiple copies in genome for most of the genes,including fad2 genes.The research cloned nine fad2 genes from 3 varieties of B.rapa and 3 varieties of B.oleracea,respectively.Alignment of the nine fad2 sequences from B.rapa and B.oleracea detected 6 single nucleotide polymorphic sites,which resulted in 6 amino-acid substitutions.The nucleotide substitutions at position 743 bp in the fad2-A gene and position 947 bp in the fad2-C gene were used as 3' end of allele-specific primers.In use of the allele-specific primers to amplify fad2 gene,we could identify if the fad2 gene originated from A genome or C genome.Besides,the research found that fad2 genes in C genome are more conserved in evolutionary process than those in A genome.The fad2 expression data reported in this study revealed that fad2-A from B.rapa was not only expressed in siliques same as fad2-C from B.oleracea,but also expressed in a high level in stems.Not even the less,fad2 gene from B.napus was expressed higher in roots and flowers.All these results provided evidences that fad2,though it was expressed differently in B.rapa and B.oleracea,but it was regulated by the same approach in B.napus.展开更多
As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representat...As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representative in GL compounds,which corresponds to the process from 3-methylthiopropyl ds-GL to 3-methylthiopropyl GL catalyzed by sulfotransferase(SOT).However,due to the lack of the crystallographic structure of SOT complexed with the 3-methylthiopropyl GL,little is known about this sulfonation process.Fortunately,the crystal structure of SOT 18 from Arabidopsis thaliana(At SOT18)containing the substance(sinigrin)similar to 3-methylthiopropyl GL has been determined.To understand the enzymatic mechanism,we employed molecular dynamics(MD)simulation and quantum mechanics combined with molecular mechanics(QM/MM)methods to study the conversion from ds-sinigrin to sinigrin catalyzed by AtSOT18.The calculated results demonstrate that the reaction occurs through a concerted dissociative mechanism.Moreover,Lys93,Thr96,Thr97,Tyr130,His155,and two enzyme peptide chains(Pro92-Lys93 and Gln95-Thr96-Thr97)play a role in positioning the substrates and promoting the catalytic reaction by stabilizing the transition state geometry.Particularly,His155 acts as a catalytic base while Lys93 acts as a catalytic acid in the reaction process.The presently proposed concerted dissociative mechanism explains the role of At SOT18 in sinigrin biosynthesis,and could be instructive for the study of GL biosynthesis catalyzed by other SOTs.展开更多
文摘The effects of ultradry storage on the activity of ATPase and fluidity of plasma membrane in Chinese cabbage (Brassica pekinensis (Lour.) Rupr.) and elm ( Ulmus pumila L.) seeds were investigated. The results indicated that no significant differences in the activity of ATPase and the micro- viscosity of plasma membrane of ultradried (UD) seeds could be found as compared to the control seeds stored under -20 degreesC, although there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of UD seeds. This implied that ultradry seed storage could protect the integrity of the membrane, maintain its physiological function and improve the storability of seeds. The relationship between sugar and desiccation tolerance of UD seeds was analysed using the HPLC. The results showed that the ratio of reducing to nonreducing sugar was lower in UD seeds than that in control. The content of sucrose and stachyose in elm and Chinese cabbage UD seeds was related to their desiccation tolerance, while no stachyose was detected in corn (Zea mays L.) seeds. This could be one of the reasons for its sensitivity to desiccation.
基金Supported by National Natural Science Foundation of China(3117207430700071)National Natural Science Foundation of Shandong Province(ZR2010CL002)~~
文摘[Objective] This study aimed to analyze tyrosinase activity and its expression in Varicorhinus macrolepis. [Method] V. macrolepis was used as experimental material for the analysis and research of tyrosinase in nine kinds of organs and tissues of male and female V. macrolepis individuals by using polyacrylamide gel electrophoresis and biochemical staining method, spectrophotometry and enzyme histochemical technology. [Result] Tyrosinase exists in the liver and pancreas, intestine and spleen of female and male V. macrolepis and in the gallbladder of male V. macrolepis. Tyrosinase activities in various tissues of V. macrolepis varied largely. Specifically, tyrosinase activities in the spleen was the maximum, which was higher in female V. macrolepis than in males. According to the enzyme histochemistry results, strong positive signals of tyrosinase existed in the spleen, intestine, liver and pancreas and gallbladder of V. macrolepis, which was the strongest in the spleen. [Conclusion] In this paper, research on tissue localization of tyrosinase in V. macrolepis had been first reported, which provided theoretical basis for further exploring the functions of tyrosinase in V. macrolepis.
文摘AIM:To evaluate the value of ABC(D) stratification [combination of serum pepsinogen and Helicobacter pylori(H.pylori) antibody]of patients with gastric cancer.METHODS:Ninety-five consecutive patients with gastric cancer were enrolled into the study.The serum pepsinogenⅠ(PGⅠ) /pepsinogenⅡ(PGⅡ) and H.pylori antibody levels were measured.Patients were classified into five groups of ABC(D) stratification according to their serological status.Endoscopic findings of atrophic gastritis and histological differentiation were also analyzed in relation to the ABC(D) stratification.RESULTS:The mean patient age was(67.9±8.9) years.Three patients(3.2%) were classified into group A,7 patients(7.4%) into group A',27 patients(28.4%) into group B,54 patients(56.8%) into group C,and 4patients(4.2%) into group D,respectively.There were only three cases in group A when the patients taking acid proton pump inhibitors and those who had undergone eradication therapy for H.pylori(group A') were excluded.These three cases had mucosal atrophy in the grey zone according to the diagnostic manual of ABC(D) stratification.Histologically,the mean age of the patients with well differentiated adenocarcinoma was significantly higher than that of the patients with poorly differentiated adenocarcinoma(P<0.05) .There were no differences in the pattern of atrophy in the endoscopies between the well differentiated and poorly differentiated groups.CONCLUSION:ABC(D) stratification is a good method for screening patients with gastric cancers.Endoscopy is needed for grey zone cases to check the extent of mucosal atrophy.
基金Supported by the National Natural Science Foundation of China(No.41230963)the National Basic Research Program of China(973 Program)(No.2011CB403604)+2 种基金the"135"Fund of Institute of Oceanology,Chinese Academy of Sciences(No.2012I0060102)the Innovative Research Group Funding of the National Natural Science Foundation of China(No.41121064)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020305)
文摘DNA barcoding provides accurate stages. Single-gene-targeted metagenomic analysis identification of zooplankton species through all life based on DNA barcode databases can facilitate long- term monitoring of zooplankton communities. With the help of the available zooplankton databases, the zooplankton community of the Changjiang （Yangtze） River estuary was studied using a single-gene-targeted metagenomic method to estimate the species richness of this community. A total of 856 mitocbondrial cytochrome oxidase subunit 1 （coxl） gene sequences were determined. The environmental barcodes were clustered into 70 molecular operational taxonomic units （MOTUs）. Forty-two MOTUs matched barcoded marine organisms with more than 90% similarity and were assigned to either the species （similarity〉96%） or genus level （similarity〈96%）. Sibling species could also be distinguished. Many species that were overlooked by morphological methods were identified by molecular methods, especially gelatinous zooplankton and merozooplankton that were likely sampled at different life history phases. Zooplankton community structures differed significantly among all of the samples. The MOTU spatial distributions were influenced by the ecological habits of the corresponding species. In conclusion, single-gene-targeted metagenomic analysis is a useful tool for zooplankton studies, with which specimens from all life history stages can be identified quickly and effectively with a comprehensive database.
基金Supported by the National Natural Science Foundation of China (31301357)the Natural Science Foundation of Jiangsu Province,China (BK20130719)
文摘The fatty acid desaturase 2(fad2) gene was proven to be a major locus for high oleic acid(C18:1).Brassica napus is an amphidiploid species originating from a spontaneous hybridization of Brassica rapa and Brassica oleracea.B.napus contains multiple copies in genome for most of the genes,including fad2 genes.The research cloned nine fad2 genes from 3 varieties of B.rapa and 3 varieties of B.oleracea,respectively.Alignment of the nine fad2 sequences from B.rapa and B.oleracea detected 6 single nucleotide polymorphic sites,which resulted in 6 amino-acid substitutions.The nucleotide substitutions at position 743 bp in the fad2-A gene and position 947 bp in the fad2-C gene were used as 3' end of allele-specific primers.In use of the allele-specific primers to amplify fad2 gene,we could identify if the fad2 gene originated from A genome or C genome.Besides,the research found that fad2 genes in C genome are more conserved in evolutionary process than those in A genome.The fad2 expression data reported in this study revealed that fad2-A from B.rapa was not only expressed in siliques same as fad2-C from B.oleracea,but also expressed in a high level in stems.Not even the less,fad2 gene from B.napus was expressed higher in roots and flowers.All these results provided evidences that fad2,though it was expressed differently in B.rapa and B.oleracea,but it was regulated by the same approach in B.napus.
基金supported by the National Natural Science Foundation of China(No.21973005)。
文摘As the major and abundant type of glucosinolates(GL)in plants,sinigrin has potential functions in promoting health and insect defense.The final step in the biosynthesis of sinigrin core structure is highly representative in GL compounds,which corresponds to the process from 3-methylthiopropyl ds-GL to 3-methylthiopropyl GL catalyzed by sulfotransferase(SOT).However,due to the lack of the crystallographic structure of SOT complexed with the 3-methylthiopropyl GL,little is known about this sulfonation process.Fortunately,the crystal structure of SOT 18 from Arabidopsis thaliana(At SOT18)containing the substance(sinigrin)similar to 3-methylthiopropyl GL has been determined.To understand the enzymatic mechanism,we employed molecular dynamics(MD)simulation and quantum mechanics combined with molecular mechanics(QM/MM)methods to study the conversion from ds-sinigrin to sinigrin catalyzed by AtSOT18.The calculated results demonstrate that the reaction occurs through a concerted dissociative mechanism.Moreover,Lys93,Thr96,Thr97,Tyr130,His155,and two enzyme peptide chains(Pro92-Lys93 and Gln95-Thr96-Thr97)play a role in positioning the substrates and promoting the catalytic reaction by stabilizing the transition state geometry.Particularly,His155 acts as a catalytic base while Lys93 acts as a catalytic acid in the reaction process.The presently proposed concerted dissociative mechanism explains the role of At SOT18 in sinigrin biosynthesis,and could be instructive for the study of GL biosynthesis catalyzed by other SOTs.
