In order to clarify cleavage efficiency of a multi-ribozyme expression system on their substrates,plasmids containing 20 cis-acting hammerhead ribozymes for self-cleavage and 10 trans-acting hammerhead ribozymes targe...In order to clarify cleavage efficiency of a multi-ribozyme expression system on their substrates,plasmids containing 20 cis-acting hammerhead ribozymes for self-cleavage and 10 trans-acting hammerhead ribozymes targeted on MDR1 and MRP1 substrates,the target plasmids pGEM-MDR1 and pGEM-MRP1 were constructed by employing PCR and DNA recombination.The endonuclease＇s digestion and DNA sequencing confirmed exactness of the multi-ribozyme expression systems and the target plasmids.The repeated self-cleavage tests revealed that the cisacting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and trans-acting hammerhead ribozymes 196 Rz and 210 Rz were released.The cleavage efficiencies of liberated ribozymes on their targets were evaluated in vitro and the results indicate that 196 Rz and 210 Rz were able to cleave the MDR1 and MRP1 RNA substrates.The profile of cleavage reaction shows that the cleavage efficiencies were correlated with the numbers of transacting hammerhead ribozymes contained in the multi-ribozyme expression systems,as well as the multi-ribozyme system is much better than the single ribozyme.Test of various concentrations of Mg^2＋ reveals that ribozyme cleavage reactions were dependent on Mg^2＋ concentration.The plot of lg（kobs） vs.lg[Mg^2＋] displays a linear relationship in the concentration range observed（2.5―20 mmol/L）.展开更多
To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hamme...To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.展开更多
Using the Nevanlinna theory of the value distribution of meromorphic functions and theory of differential algebra, we investigate the problem of the forms of meromorphic solutions of some specific systems of generaliz...Using the Nevanlinna theory of the value distribution of meromorphic functions and theory of differential algebra, we investigate the problem of the forms of meromorphic solutions of some specific systems of generalized higher order algebraic differential equations with exponential coefficients and obtain some results.展开更多
Since its discovery in the 1980s,the insect cell-baculovirus expression vector system(IC-BEVS)has been widely used in biomedical applications,such as recombinant protein expression,drug screening,vaccine development,g...Since its discovery in the 1980s,the insect cell-baculovirus expression vector system(IC-BEVS)has been widely used in biomedical applications,such as recombinant protein expression,drug screening,vaccine development,gene therapy and so on[1].As a eukaryotic system,IC-BEVS has great development prospects due to its advantages such as high safety,simple operation,simultaneous expression of multi-subunit proteins,and suitability for large-scale cultivation[2].展开更多
Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification ava...Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.展开更多
Systemic lupus erythematosus(SLE)is a systemic autoimmune disease characterized by abnormal cellular and humoral immune responses and excessive autoantibody production.The precise pathologic mechanism of SLE remains e...Systemic lupus erythematosus(SLE)is a systemic autoimmune disease characterized by abnormal cellular and humoral immune responses and excessive autoantibody production.The precise pathologic mechanism of SLE remains elusive.The advent of single-cell RNA sequencing(scRNA-seq)enables unbiased analysis of the molecular differences of cell populations at the single-cell level.We used scRNA-seq to profile the transcriptomes of peripheral blood mononuclear cells from an SLE patient compared with a healthy control(HC).A total of 16,021 cells were analyzed and partitioned into 12 distinct clusters.The marker genes of each cluster and the four major immune cell types(B cells,CD4+T cells,CD8+T cells,myeloid cells,and NK cells)were determined.Moreover,several genes involved in antigen processing and presentation through MHCII were highly enriched.GO enrichment analyses revealed abnormal gene expression patterns and signaling pathways in SLE.Of note,pseudotime analysis revealed that there was a different lineage hierarchy in the peripheral blood mononuclear cells(PBMCs)of the SLE patient,indicating that the cell states were substantially altered under disease conditions.Our analysis provides a comprehensive map of the cell types and states of the PBMCs of SLE patients at the single-cell level for a better understanding of the pathogenesis,diagnosis,and treatment of SLE.展开更多
Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin （PLFN）. A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the cha...Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin （PLFN）. A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the characters of translational fusions from gene and expression vector plasmid. A 1 077 bp fragment of the gene from PLF was cloned from mammary gland tissue of the lactating sow on the third day by RT-PCR; the gene was connected with the vector plasmid pPG612.1 and transformed into the host strain JM109. The recombinant expression vector plasmid pPG612-PLFN was created and identified by using plasmid extraction, PCR, restriction enzyme digestion and sequence analysis. The recombinant plasmid was transformed into Lactobacillus casei ATCC393, Lactobacillus plantarum KLDS 1.0344, Lactobacillus paracasei KLDS 1.0652 and Lactobacillus pentosus KLDS 1.0413 by electroporation, and produced the recombinant strains of pPG612-PLFN/L, casei, pPG612-PLFN/L, plantarum, pPG612-PLFN/ L. paracasei and pPG612-PLFN/L, pentosus, respectively. The results indicated that PLFN gene had inserted into the expression vectors and achieved multiple Laetobacillus expression systems. It electes the base for the expression and production of recombinant porcine lactoferrin in Lactobaeillus展开更多
Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. Th...Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by Western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Results: Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Conclusions: Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.展开更多
Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, expos...Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, exposing hydrophobic pockets. This property can be utilized for purification purposes, as these pockets bind to phenyl sepharose resin with high affinity. Washing with EDTA chelates the Ca2+ ions from the protein, inducing a conformational change back to the more folded state and eluting the protein from the column. We describe herein the use of a protein expression and purification technique using the calmodulin variant and a short linker for proteolytic cleavage by the mutant NIa-Pro tobacco etch virus protease. We have shown this approach to be useful in obtaining purified quantities of various small proteins that could not be expressed using other methods, including high enough concentrations of a designed WW domain protein for NMR structural analysis. We have also obtained promising results on the usefulness of this procedure to express and purify zinc finger proteins without the addition of zinc ions or other cofactors.展开更多
A facial expression emotion recognition based human-robot interaction(FEER-HRI) system is proposed, for which a four-layer system framework is designed. The FEERHRI system enables the robots not only to recognize huma...A facial expression emotion recognition based human-robot interaction(FEER-HRI) system is proposed, for which a four-layer system framework is designed. The FEERHRI system enables the robots not only to recognize human emotions, but also to generate facial expression for adapting to human emotions. A facial emotion recognition method based on2D-Gabor, uniform local binary pattern(LBP) operator, and multiclass extreme learning machine(ELM) classifier is presented,which is applied to real-time facial expression recognition for robots. Facial expressions of robots are represented by simple cartoon symbols and displayed by a LED screen equipped in the robots, which can be easily understood by human. Four scenarios,i.e., guiding, entertainment, home service and scene simulation are performed in the human-robot interaction experiment, in which smooth communication is realized by facial expression recognition of humans and facial expression generation of robots within 2 seconds. As a few prospective applications, the FEERHRI system can be applied in home service, smart home, safe driving, and so on.展开更多
This study examined the gene expression patterns of peripheral blood mononuclear cells （PBMCs） in patients with systemic lupus erythematosus （SLE） by using serial analysis of gene expression （SAGE） technology. F...This study examined the gene expression patterns of peripheral blood mononuclear cells （PBMCs） in patients with systemic lupus erythematosus （SLE） by using serial analysis of gene expression （SAGE） technology. Following the construction of serial analysis of gene expression （SAGE） library of PBMCs collected from 3 cases of familial SLE patients, a large scale of tag Sequencing was performed. The data extracted from sequencing files was analyzed with SAGE 2000 V 4.5 software. The top 30 expressed genes of SLE patients were uploaded to http：//david.niaid.nih.gov/david/ease.htm and the functional classification of genes was obtained. The differences among those expressed gene were analyzed by Chi-square tests. The results showed that a total of 1286 unique SAGE tags were identified from 1814 individual SAGE tags. Among the 1286 unique tags, 86.8% had single copy, and only 0.2% tags had more than 20 copies. And 68.4% of the tags matched known expressed sequences, 41.1% of which matched more than one known expressed sequence. About 31.6% of the tags had no match and could represent potentially novel genes. Approximately one third of the top 30 genes were ribosomal protein, and the rest were genes related to metabolism or with unknown functions. Eight tags were found to express differentially in SAGE library of SLE patients. This study draws a profile of gene expression patterns of PBMCs in patients with SLE. Comparison of SAGE database from PBMCs between normal individuals and SLE patients will help us to better understand the pathogenesis of SLE.展开更多
The genetic microarrays give to researchers a huge amount of data of many diseases represented by intensities of gene expression. In genomic medicine gene expression analysis is guided to find strategies for preventio...The genetic microarrays give to researchers a huge amount of data of many diseases represented by intensities of gene expression. In genomic medicine gene expression analysis is guided to find strategies for prevention and treatment of diseases with high rate of mortality like the different cancers. So, genomic medicine requires the use of complex information technology. The purpose of our paper is to present a multi-agent system developed in order to improve gene expression analysis with the automation of tasks about identification of genes involved in a cancer, and classification of tumors according to molecular biology. Agents that integrate the system, carry out reading files of intensity data of genes from microarrays, pre-processing of this information, and with machine learning methods make groups of genes involved in the process of a disease as well as the classification of samples that could propose new subtypes of tumors difficult to identify based on their morphology. Our results we prove that the multi-agent system requires a minimal intervention of user, and the agents generate knowledge that reduce the time and complexity of the work of prevention and diagnosis, and thus allow a more effective treatment of tumors.展开更多
Helicobacterpylori （1f. pylori） infection causes peptic and duodenal diseases in humans. Among a 32-protein family of outer membrane proteins, a porin-like protein, HopE, has been a subject of note, mainly for its c...Helicobacterpylori （1f. pylori） infection causes peptic and duodenal diseases in humans. Among a 32-protein family of outer membrane proteins, a porin-like protein, HopE, has been a subject of note, mainly for its conservative nature among 11. pylori, and for its potential as a vaccine candidate. To achieve stable surface expression of this host cell-toxic protein, hopE gene was introduced into pBAD expression system. After induction with arabinose, all 15 randomly-chosen E. coli LMG 194 colonies from 3 successive passages could express Hope protein, while only 1 from 5 E. coli colonies that contained lac operon-regulated plasmid encoding hopE gene could express HopE. Indirect immunofluorescence confirmed the expression of HopE on E. coli cell surface展开更多
Objective: To study the expression and role of plasminogen system in the process of restenosis. Methods: We established a doubleinjury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arteria...Objective: To study the expression and role of plasminogen system in the process of restenosis. Methods: We established a doubleinjury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial restenosis. The time course of tissue plaminogen activator (tPA), urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor1 (PAI1) was investigated by immunohistochemistry. The mRNA expression of uPA and uPAR were detected after vascular procedures by in situ hybridization. Results: In uninjured arteries, the weak expression of tPA and PAI1 was detected in intimal and endothelial cells. The expression of tPA, uPA, uPAR and PAI1 was significantly induced after doubleinjury, but after double injury 14d, the expression of tPA restore to preinjury levels. The expression of uPA and uPAR in intimal was higher than that of media and maintain high levels in intimal within 42d and 56d. Conclusion: Whereas tPA is primarily involved in clot dissolution and play a limited role in the process of restenosis, in plasminogen system, uPA and uPAR play a prominent role in the process of restenosis.展开更多
The principle and the basic steps of the transient assay system for the functional assessment of early response genes on the powdery mildew infected barley or wheat leaves were summarized in brief. The development of ...The principle and the basic steps of the transient assay system for the functional assessment of early response genes on the powdery mildew infected barley or wheat leaves were summarized in brief. The development of this technology and its extensive application were reviewed. Future studies on this approach were recommended in this paper.展开更多
Objective：CYP1A2 and NADPH-CYP450 oxidoreductase（POR）were expressed in the baculovirus/ Spodoptera frugiperda（sf9）system.The aim of this study was to investigate the effects of heme precursors on the expression o...Objective：CYP1A2 and NADPH-CYP450 oxidoreductase（POR）were expressed in the baculovirus/ Spodoptera frugiperda（sf9）system.The aim of this study was to investigate the effects of heme precursors on the expression of CYP1A2 and POR.Methods：The heme precursors[δ-Aminolaevulinic Acid（5-ALA）,Fe^3＋and hemin]were introduced into the system to evaluate their effects on the expression of CYP1A2,POR and their co-expression.All the proteins were identified using immunoblotting,CO-difference spectroscopy,or cytochrome c assay.Results：In the present study,functional CYP1A2 and POR were successfully expressed in the baculovirus/sf9 system,and both of them showed high activities.Co-addition of 5-ALA and Fe^3＋significantly improved expression of CYP1A2 by about 50%compared with the addition of 5-ALA,Fe^3＋or hemin alone.Either co-addition of 5-ALA and Fe^3＋or addition of 5-ALA or Fe^3＋alone improved the POR expression level 2 fold and its activity 7-10 fold compared with control（no addition）.However,unlike CYP1A2,there was no difference between the co-addition and addition of these heme precursors alone.Different ratios of BvCYP1A2 to BvPOR also affected the co-expression of CYP1A2 and POR,with a 3：1 ratio of BvCYP1A2/BvPOR significantly increasing their co-expression.Surprisingly,the addition of 0.1 mM 5-ALA or Fe^3＋alone,but not their co- addition,could significantly improve the CYP1A2 and POR co-expression（P〈0.05）.Conclusion：5-ALA and Fe^3＋increased the expression of CYP1A2 and POR in a baculovirus/sf9 system,but the pattern of their expression was different between their expression alone and co-expression.展开更多
The evolution of the central nervous system（CNS） is one of the most striking changes during the transition from invertebrates to vertebrates. As a major source of genetic novelties,gene duplication might play an imp...The evolution of the central nervous system（CNS） is one of the most striking changes during the transition from invertebrates to vertebrates. As a major source of genetic novelties,gene duplication might play an important role in the functional innovation of vertebrate CNS.In this study,we focused on a group of CNS-biased genes that duplicated during early vertebrate evolution.We investigated the tempo-spatial expression patterns of 33 duplicate gene families and their orthologs during the embryonic development of the vertebrate Xenopus laevis and the cephalochordate Brachiostoma belcheri.Almost all the identified duplicate genes are differentially expressed in the CNS in Xenopus embryos,and more than 50%and 30%duplicate genes are expressed in the telencephalon and mid-hindbrain boundary,respectively,which are mostly considered as two innovations in the vertebrate CNS.Interestingly,more than 50%of the amphioxus orthologs do not show apparent expression in the CNS in amphioxus embryos as detected by in situ hybridization,indicating that some of the vertebrate CNS-biased duplicate genes might arise from non-CNS genes in invertebrates.Our data accentuate the functional contribution of gene duplication in the CNS evolution of vertebrate and uncover an invertebrate non-CNS history for some vertebrate CNS-biased duplicate genes.展开更多
CD93 and GAIP-interacting protein, C termius （GIPC） have been shown to interactively alter phagocytic processes of immune cells. CD93 and GIPC expression and localization during cen-tral nervous system inflammation ...CD93 and GAIP-interacting protein, C termius （GIPC） have been shown to interactively alter phagocytic processes of immune cells. CD93 and GIPC expression and localization during cen-tral nervous system inflammation have not yet been reported. In this study, we established a rat model of brain inlfammation by lipopolysaccharide injection to the lateral ventricle. In the brain of rats with inlfammation, western blots showed increased CD93 expression that decreased over time. GIPC expression was unaltered. Immunohistochemistry demonstrated extensive distribution of CD93 expression mainly in cell membranes in the cerebral cortex. After lipopoly-saccharide stimulation, CD93 expression increased and then reduced, with distinct staining in the cytoplasm and nucleus. Double immunolfuorescence staining in cerebral cortex of normal rats showed that CD93 and GIPC widely expressed in resting microglia and neurons. CD93 was mainly expressed in microglial and neuronal cell membranes, while GIPC was expressed in both cell membrane and cytoplasm. In the cerebral cortex at 9 hours after model establishment, CD93-immunoreactive signal diminished in microglial membrane, with cytoplasmic transloca-tion and aggregation detected. GIPC localization was unaltered in neurons and microglia. These results are the ifrst to demonstrate CD93 participation in pathophysiological processes of central nervous system inlfammation.展开更多
基金Supported by Fund of "T. J. Martell Foundation for AIDS,Leukemia and Cancer Research"Fund of Shenzhen Bureau of Science and Technology,China(No.20008)
文摘In order to clarify cleavage efficiency of a multi-ribozyme expression system on their substrates,plasmids containing 20 cis-acting hammerhead ribozymes for self-cleavage and 10 trans-acting hammerhead ribozymes targeted on MDR1 and MRP1 substrates,the target plasmids pGEM-MDR1 and pGEM-MRP1 were constructed by employing PCR and DNA recombination.The endonuclease＇s digestion and DNA sequencing confirmed exactness of the multi-ribozyme expression systems and the target plasmids.The repeated self-cleavage tests revealed that the cisacting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and trans-acting hammerhead ribozymes 196 Rz and 210 Rz were released.The cleavage efficiencies of liberated ribozymes on their targets were evaluated in vitro and the results indicate that 196 Rz and 210 Rz were able to cleave the MDR1 and MRP1 RNA substrates.The profile of cleavage reaction shows that the cleavage efficiencies were correlated with the numbers of transacting hammerhead ribozymes contained in the multi-ribozyme expression systems,as well as the multi-ribozyme system is much better than the single ribozyme.Test of various concentrations of Mg^2＋ reveals that ribozyme cleavage reactions were dependent on Mg^2＋ concentration.The plot of lg（kobs） vs.lg[Mg^2＋] displays a linear relationship in the concentration range observed（2.5―20 mmol/L）.
基金Supported by Fund of Shenzhen Bureau of Science and Technology, China(No.20008).
文摘To improve catalytic activity of ribozyme on its substrate, the multi-ribozyme expression system was designed and constructed from 20 cis-acting hammerhead ribozymes undergoing self-cleavage with 10 trans-acting hammerhead ribozymes inserted alternatively regularly and the plasmid of pGEM-MDR1/MRP1 used to transcribe the MDR1/MRPl（196/210） substrate containing double target sites was also constructed by DNA recombination. Endonuclease digestion analysis and DNA sequencing indicate all the recombinant plasmids were correct. The clea- vage activities were evaluated for the multi-ribozyme expression system on the MDR1/MRP1 substrate in the cell free system. The results demonstrate that the cis-acting hammerhead ribozymes in the multi-ribozyme expression system were able to cleave themselves and the 72 nt of 196Rz and the 71 nt of 210Rz trans-acting hammerhead ribozymes were liberated effectively, and the trans-acting hammerhead ribozymes released were able to act on the MDR1/MRP1 double target RNA substrate and cleave the target RNA at specific sites effectively. The multi- ribozyme expression system of the [Coat＇A196Rz/Coat＇B210Rz]5 is more significantly superior to that of the [Coat＇A 196Rz/Coat＇B210Rz] 1 in cleavage of RNA substrate. The fractions cleaved by [Coat＇A 196Rz/Coat＇B210Rz]5 on the MDR1/MRP1 substrate for 8 h at observed temperatures showed no marked difference. The studies of Mg^2＋ on cleavage efficiency indicate that cleavage reaction is dependent on Mg^2＋ ions concentration. The plot of lg（kobs） vs. lgc（Mg^2＋） displays a linear relationship between 2.5 mmol/L and 20 mmol/L Mg^2＋. It suggests that Mg^2＋ ions play a crucial role in multi-ribozyme cleavage on the substrate.
基金Project Supported by the Natural Science Foundation of China (10471065)the Natural Science Foundation of Guangdong Province (04010474)
文摘Using the Nevanlinna theory of the value distribution of meromorphic functions and theory of differential algebra, we investigate the problem of the forms of meromorphic solutions of some specific systems of generalized higher order algebraic differential equations with exponential coefficients and obtain some results.
文摘Since its discovery in the 1980s,the insect cell-baculovirus expression vector system(IC-BEVS)has been widely used in biomedical applications,such as recombinant protein expression,drug screening,vaccine development,gene therapy and so on[1].As a eukaryotic system,IC-BEVS has great development prospects due to its advantages such as high safety,simple operation,simultaneous expression of multi-subunit proteins,and suitability for large-scale cultivation[2].
文摘Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.
基金the National Natural Science Foundation of China(Grant No.81671596)the Natural Science Foundation of Guangxi(Grant No.2019GXNSFBA245032,and No.2017GXNSFAA198375)+6 种基金the Guangxi Science and Technology Plan Project(Gui Ke AD20238021)the National Science Foundation for Young Scientists of China(Grant No.31700795)the science and technology plan of Shenzhen(No.JCYJ20170307095606266)Shenzhen science and technology research foundation(JCYJ20160422154407256)Sanming project of medicine in Shenzhen,the group of Rheumatology and Immunology led by Xiaofeng Zeng of Peking Union medical college Hospital and Dongzhou Liu in Shenzhen People’s Hospital(SYJY201704 and SYJY201705)the open funds of the Guangxi Key Laboratory of Tumor Immunology and Microenvironmental Regulation(2019KF004)Guilin science research and technology development project(20190218-5-5).
文摘Systemic lupus erythematosus(SLE)is a systemic autoimmune disease characterized by abnormal cellular and humoral immune responses and excessive autoantibody production.The precise pathologic mechanism of SLE remains elusive.The advent of single-cell RNA sequencing(scRNA-seq)enables unbiased analysis of the molecular differences of cell populations at the single-cell level.We used scRNA-seq to profile the transcriptomes of peripheral blood mononuclear cells from an SLE patient compared with a healthy control(HC).A total of 16,021 cells were analyzed and partitioned into 12 distinct clusters.The marker genes of each cluster and the four major immune cell types(B cells,CD4+T cells,CD8+T cells,myeloid cells,and NK cells)were determined.Moreover,several genes involved in antigen processing and presentation through MHCII were highly enriched.GO enrichment analyses revealed abnormal gene expression patterns and signaling pathways in SLE.Of note,pseudotime analysis revealed that there was a different lineage hierarchy in the peripheral blood mononuclear cells(PBMCs)of the SLE patient,indicating that the cell states were substantially altered under disease conditions.Our analysis provides a comprehensive map of the cell types and states of the PBMCs of SLE patients at the single-cell level for a better understanding of the pathogenesis,diagnosis,and treatment of SLE.
基金Supported by National Natural Science Foundation of China (30871809,31072057)Principal Fund of Northeast Agricultural University
文摘Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin （PLFN）. A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the characters of translational fusions from gene and expression vector plasmid. A 1 077 bp fragment of the gene from PLF was cloned from mammary gland tissue of the lactating sow on the third day by RT-PCR; the gene was connected with the vector plasmid pPG612.1 and transformed into the host strain JM109. The recombinant expression vector plasmid pPG612-PLFN was created and identified by using plasmid extraction, PCR, restriction enzyme digestion and sequence analysis. The recombinant plasmid was transformed into Lactobacillus casei ATCC393, Lactobacillus plantarum KLDS 1.0344, Lactobacillus paracasei KLDS 1.0652 and Lactobacillus pentosus KLDS 1.0413 by electroporation, and produced the recombinant strains of pPG612-PLFN/L, casei, pPG612-PLFN/L, plantarum, pPG612-PLFN/ L. paracasei and pPG612-PLFN/L, pentosus, respectively. The results indicated that PLFN gene had inserted into the expression vectors and achieved multiple Laetobacillus expression systems. It electes the base for the expression and production of recombinant porcine lactoferrin in Lactobaeillus
基金supported financially by Iran National Science Foundation(INSF)grant number 91004026
文摘Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by Western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Results: Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Conclusions: Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.
文摘Calmodulin from Homo sapiens is an α-helical calcium-binding protein that expresses to high levels in E. coli. When the N-terminus of a calmodulin variant is bound to Ca2+, it undergoes a conformational change, exposing hydrophobic pockets. This property can be utilized for purification purposes, as these pockets bind to phenyl sepharose resin with high affinity. Washing with EDTA chelates the Ca2+ ions from the protein, inducing a conformational change back to the more folded state and eluting the protein from the column. We describe herein the use of a protein expression and purification technique using the calmodulin variant and a short linker for proteolytic cleavage by the mutant NIa-Pro tobacco etch virus protease. We have shown this approach to be useful in obtaining purified quantities of various small proteins that could not be expressed using other methods, including high enough concentrations of a designed WW domain protein for NMR structural analysis. We have also obtained promising results on the usefulness of this procedure to express and purify zinc finger proteins without the addition of zinc ions or other cofactors.
基金supported by the National Natural Science Foundation of China(61403422,61273102)the Hubei Provincial Natural Science Foundation of China(2015CFA010)+1 种基金the Ⅲ Project(B17040)the Fundamental Research Funds for National University,China University of Geosciences(Wuhan)
文摘A facial expression emotion recognition based human-robot interaction(FEER-HRI) system is proposed, for which a four-layer system framework is designed. The FEERHRI system enables the robots not only to recognize human emotions, but also to generate facial expression for adapting to human emotions. A facial emotion recognition method based on2D-Gabor, uniform local binary pattern(LBP) operator, and multiclass extreme learning machine(ELM) classifier is presented,which is applied to real-time facial expression recognition for robots. Facial expressions of robots are represented by simple cartoon symbols and displayed by a LED screen equipped in the robots, which can be easily understood by human. Four scenarios,i.e., guiding, entertainment, home service and scene simulation are performed in the human-robot interaction experiment, in which smooth communication is realized by facial expression recognition of humans and facial expression generation of robots within 2 seconds. As a few prospective applications, the FEERHRI system can be applied in home service, smart home, safe driving, and so on.
基金This project was supported by a grant form the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry (No [2002]247)
文摘This study examined the gene expression patterns of peripheral blood mononuclear cells （PBMCs） in patients with systemic lupus erythematosus （SLE） by using serial analysis of gene expression （SAGE） technology. Following the construction of serial analysis of gene expression （SAGE） library of PBMCs collected from 3 cases of familial SLE patients, a large scale of tag Sequencing was performed. The data extracted from sequencing files was analyzed with SAGE 2000 V 4.5 software. The top 30 expressed genes of SLE patients were uploaded to http：//david.niaid.nih.gov/david/ease.htm and the functional classification of genes was obtained. The differences among those expressed gene were analyzed by Chi-square tests. The results showed that a total of 1286 unique SAGE tags were identified from 1814 individual SAGE tags. Among the 1286 unique tags, 86.8% had single copy, and only 0.2% tags had more than 20 copies. And 68.4% of the tags matched known expressed sequences, 41.1% of which matched more than one known expressed sequence. About 31.6% of the tags had no match and could represent potentially novel genes. Approximately one third of the top 30 genes were ribosomal protein, and the rest were genes related to metabolism or with unknown functions. Eight tags were found to express differentially in SAGE library of SLE patients. This study draws a profile of gene expression patterns of PBMCs in patients with SLE. Comparison of SAGE database from PBMCs between normal individuals and SLE patients will help us to better understand the pathogenesis of SLE.
文摘The genetic microarrays give to researchers a huge amount of data of many diseases represented by intensities of gene expression. In genomic medicine gene expression analysis is guided to find strategies for prevention and treatment of diseases with high rate of mortality like the different cancers. So, genomic medicine requires the use of complex information technology. The purpose of our paper is to present a multi-agent system developed in order to improve gene expression analysis with the automation of tasks about identification of genes involved in a cancer, and classification of tumors according to molecular biology. Agents that integrate the system, carry out reading files of intensity data of genes from microarrays, pre-processing of this information, and with machine learning methods make groups of genes involved in the process of a disease as well as the classification of samples that could propose new subtypes of tumors difficult to identify based on their morphology. Our results we prove that the multi-agent system requires a minimal intervention of user, and the agents generate knowledge that reduce the time and complexity of the work of prevention and diagnosis, and thus allow a more effective treatment of tumors.
基金support by National Natural Science Foundation of China(61202354,51507084)Nanjing University of Post and Telecommunications Science Foundation(NUPTSF)(NT214203)
文摘Helicobacterpylori （1f. pylori） infection causes peptic and duodenal diseases in humans. Among a 32-protein family of outer membrane proteins, a porin-like protein, HopE, has been a subject of note, mainly for its conservative nature among 11. pylori, and for its potential as a vaccine candidate. To achieve stable surface expression of this host cell-toxic protein, hopE gene was introduced into pBAD expression system. After induction with arabinose, all 15 randomly-chosen E. coli LMG 194 colonies from 3 successive passages could express Hope protein, while only 1 from 5 E. coli colonies that contained lac operon-regulated plasmid encoding hopE gene could express HopE. Indirect immunofluorescence confirmed the expression of HopE on E. coli cell surface
文摘Objective: To study the expression and role of plasminogen system in the process of restenosis. Methods: We established a doubleinjury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial restenosis. The time course of tissue plaminogen activator (tPA), urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor1 (PAI1) was investigated by immunohistochemistry. The mRNA expression of uPA and uPAR were detected after vascular procedures by in situ hybridization. Results: In uninjured arteries, the weak expression of tPA and PAI1 was detected in intimal and endothelial cells. The expression of tPA, uPA, uPAR and PAI1 was significantly induced after doubleinjury, but after double injury 14d, the expression of tPA restore to preinjury levels. The expression of uPA and uPAR in intimal was higher than that of media and maintain high levels in intimal within 42d and 56d. Conclusion: Whereas tPA is primarily involved in clot dissolution and play a limited role in the process of restenosis, in plasminogen system, uPA and uPAR play a prominent role in the process of restenosis.
基金supported by the National High Tech Research and Development Program,China(863 Program,222092).
文摘The principle and the basic steps of the transient assay system for the functional assessment of early response genes on the powdery mildew infected barley or wheat leaves were summarized in brief. The development of this technology and its extensive application were reviewed. Future studies on this approach were recommended in this paper.
基金NSFC(No.30771782)Natural Science Foundation of Jiangsu Province(No.BK2007233)Foundation of Nanjing Medical University(06NMUZ009)
文摘Objective：CYP1A2 and NADPH-CYP450 oxidoreductase（POR）were expressed in the baculovirus/ Spodoptera frugiperda（sf9）system.The aim of this study was to investigate the effects of heme precursors on the expression of CYP1A2 and POR.Methods：The heme precursors[δ-Aminolaevulinic Acid（5-ALA）,Fe^3＋and hemin]were introduced into the system to evaluate their effects on the expression of CYP1A2,POR and their co-expression.All the proteins were identified using immunoblotting,CO-difference spectroscopy,or cytochrome c assay.Results：In the present study,functional CYP1A2 and POR were successfully expressed in the baculovirus/sf9 system,and both of them showed high activities.Co-addition of 5-ALA and Fe^3＋significantly improved expression of CYP1A2 by about 50%compared with the addition of 5-ALA,Fe^3＋or hemin alone.Either co-addition of 5-ALA and Fe^3＋or addition of 5-ALA or Fe^3＋alone improved the POR expression level 2 fold and its activity 7-10 fold compared with control（no addition）.However,unlike CYP1A2,there was no difference between the co-addition and addition of these heme precursors alone.Different ratios of BvCYP1A2 to BvPOR also affected the co-expression of CYP1A2 and POR,with a 3：1 ratio of BvCYP1A2/BvPOR significantly increasing their co-expression.Surprisingly,the addition of 0.1 mM 5-ALA or Fe^3＋alone,but not their co- addition,could significantly improve the CYP1A2 and POR co-expression（P〈0.05）.Conclusion：5-ALA and Fe^3＋increased the expression of CYP1A2 and POR in a baculovirus/sf9 system,but the pattern of their expression was different between their expression alone and co-expression.
基金supported by the grants from the Innovation Project of Chinese Academy of Sciences(No.KSCX2-YW-R- 090)the Key State Research Program from the Ministry of Science and Technology of China(No.2007CB947201)
文摘The evolution of the central nervous system（CNS） is one of the most striking changes during the transition from invertebrates to vertebrates. As a major source of genetic novelties,gene duplication might play an important role in the functional innovation of vertebrate CNS.In this study,we focused on a group of CNS-biased genes that duplicated during early vertebrate evolution.We investigated the tempo-spatial expression patterns of 33 duplicate gene families and their orthologs during the embryonic development of the vertebrate Xenopus laevis and the cephalochordate Brachiostoma belcheri.Almost all the identified duplicate genes are differentially expressed in the CNS in Xenopus embryos,and more than 50%and 30%duplicate genes are expressed in the telencephalon and mid-hindbrain boundary,respectively,which are mostly considered as two innovations in the vertebrate CNS.Interestingly,more than 50%of the amphioxus orthologs do not show apparent expression in the CNS in amphioxus embryos as detected by in situ hybridization,indicating that some of the vertebrate CNS-biased duplicate genes might arise from non-CNS genes in invertebrates.Our data accentuate the functional contribution of gene duplication in the CNS evolution of vertebrate and uncover an invertebrate non-CNS history for some vertebrate CNS-biased duplicate genes.
基金supported by the National Natural Science Foundation of China,No.31170766the Nantong Municipal Social Undertakings Technological Innovation and Demonstration Project Foundation,No.HS2012032the Natural Science Pre-research Project Foundation of Nantong University in 2012,No.12ZY020
文摘CD93 and GAIP-interacting protein, C termius （GIPC） have been shown to interactively alter phagocytic processes of immune cells. CD93 and GIPC expression and localization during cen-tral nervous system inflammation have not yet been reported. In this study, we established a rat model of brain inlfammation by lipopolysaccharide injection to the lateral ventricle. In the brain of rats with inlfammation, western blots showed increased CD93 expression that decreased over time. GIPC expression was unaltered. Immunohistochemistry demonstrated extensive distribution of CD93 expression mainly in cell membranes in the cerebral cortex. After lipopoly-saccharide stimulation, CD93 expression increased and then reduced, with distinct staining in the cytoplasm and nucleus. Double immunolfuorescence staining in cerebral cortex of normal rats showed that CD93 and GIPC widely expressed in resting microglia and neurons. CD93 was mainly expressed in microglial and neuronal cell membranes, while GIPC was expressed in both cell membrane and cytoplasm. In the cerebral cortex at 9 hours after model establishment, CD93-immunoreactive signal diminished in microglial membrane, with cytoplasmic transloca-tion and aggregation detected. GIPC localization was unaltered in neurons and microglia. These results are the ifrst to demonstrate CD93 participation in pathophysiological processes of central nervous system inlfammation.
