Matrix attachment regions or matrix associated regions (MARs) were special DNA sequences in chromatin of eukaryotic cells that tightly associated with the nuclear matrix or scaffold in vitro after a combination of nuc...Matrix attachment regions or matrix associated regions (MARs) were special DNA sequences in chromatin of eukaryotic cells that tightly associated with the nuclear matrix or scaffold in vitro after a combination of nuclease digestion and extraction. They were also called scaffold attachment regions(SARs) . It was found that MARs could improve the expression level and the stability of foreign genes in transgenic plants. The reason might be that a transgene flanked by MARs was transmitted into the plant cells, the MARs would attach the nuclear展开更多
By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-my...By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-mycobacteria shuttle expression plasmid PBCG-8000 was constructed. The PBCG-8000 was able to replicate in both E. Coli and mycobacteria (including BCG) systems, and to confer stable kanamycin resistance upon transformants. The study should facilitate the development of BCG and other mycobacteria into multivalent vaccine vectors.展开更多
Background To describe mumps virus(MuV)used as a vector to express enhanced green fluorescent protein(EGFP)or red fluorescent protein(RFP)genes.Methods Molecular cloning technique was applied to establish the cDNA clo...Background To describe mumps virus(MuV)used as a vector to express enhanced green fluorescent protein(EGFP)or red fluorescent protein(RFP)genes.Methods Molecular cloning technique was applied to establish the cDNA clones of recombinant mumps viruses(rMuVs).rMuVs were recovered based on our reverse genetic system of MuV-S79.The properties of rMuVs were determined by growth curve,plaque assay,fluorescent microscopy and determination of fluorescent intensity.Results Three recombinant viruses replicated well in Vero cells and similarly as parental rMuV-S79,expressed heterologous genes in high levels,and were genetically stable in at least 15 passages.Conclusion rMuV-S79 is a promising platform to accommodate foreign genes like marker genes,other antigens and immunomodulators for addressing various diseases.展开更多
In recent years, research that focused on applying 'disarmed' and constructed Tiplasmid of Agrobacterium tumefaciens as a dominant vector for plant genetic engineering has developed quickly. Several vector sys...In recent years, research that focused on applying 'disarmed' and constructed Tiplasmid of Agrobacterium tumefaciens as a dominant vector for plant genetic engineering has developed quickly. Several vector systems have become especially useful in plant transformation, and a great number of foreign genes have been transferred to dicot plants by means of the leaf-disc transformation method along with the Ti-plasmid vector. Most of the transgenic plants, which bear the novel trait, can accomplish complete regeneration, and the characteristics of the new genotype can be transmitted from generation to generation in the plant cells.展开更多
The matrix attachment region (MAR) located downstream of Plastocyanin gene was isolated from the genome of pea. To study the effect of MARs on foreign gene expression in transgenic plants, T DNA vector was constructed...The matrix attachment region (MAR) located downstream of Plastocyanin gene was isolated from the genome of pea. To study the effect of MARs on foreign gene expression in transgenic plants, T DNA vector was constructed in which MARs flanked bothβ glucuronidase(GUS) gene and selectable marker neomycin phosphotransferase (NPT II) gene. The plant expression vectors were transferred into leaf discs via Agrobacterium mediated transformation procedure. The result of GUS measurement showed that pea MAR could increase transgene expression level. The mean expression levels of GUS gene expression in population containing MARs could be increased twofold when compared with that of population without MARs.展开更多
Two transgenic mouse strains , in which the expression of human factor IX (hFIX) in the milk were different significantly, were bred, and the foreign gene integration as well as the content of hFIX in the milk were de...Two transgenic mouse strains , in which the expression of human factor IX (hFIX) in the milk were different significantly, were bred, and the foreign gene integration as well as the content of hFIX in the milk were detected by PCR, Southern blot, FISH and ELISA, respectively. The results showed that approximately 50% offsprings were transgenic positive. Foreign gene integrated in mouse chromosomes was intact. The hFIX expression of each mouse in the same strain was different, the content of hFIX in the milk was (43.32±5.41)μg/mL in FIX-33 transgenic strain and (1.16±0.45)μg/mL in FIX-124 transgenic strain. Meanwhile, the hFIX gene expression between the two strains was different remarkably (P<0.01). We conclude that the characteristics of inheritance and expression in the founder were able to be transferred to their offsprings stably.展开更多
文摘Matrix attachment regions or matrix associated regions (MARs) were special DNA sequences in chromatin of eukaryotic cells that tightly associated with the nuclear matrix or scaffold in vitro after a combination of nuclease digestion and extraction. They were also called scaffold attachment regions(SARs) . It was found that MARs could improve the expression level and the stability of foreign genes in transgenic plants. The reason might be that a transgene flanked by MARs was transmitted into the plant cells, the MARs would attach the nuclear
文摘By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-mycobacteria shuttle expression plasmid PBCG-8000 was constructed. The PBCG-8000 was able to replicate in both E. Coli and mycobacteria (including BCG) systems, and to confer stable kanamycin resistance upon transformants. The study should facilitate the development of BCG and other mycobacteria into multivalent vaccine vectors.
基金supported partly by the Natural Science Foundation for Young Scholars of Zhejiang Province(LQ19H100005).
文摘Background To describe mumps virus(MuV)used as a vector to express enhanced green fluorescent protein(EGFP)or red fluorescent protein(RFP)genes.Methods Molecular cloning technique was applied to establish the cDNA clones of recombinant mumps viruses(rMuVs).rMuVs were recovered based on our reverse genetic system of MuV-S79.The properties of rMuVs were determined by growth curve,plaque assay,fluorescent microscopy and determination of fluorescent intensity.Results Three recombinant viruses replicated well in Vero cells and similarly as parental rMuV-S79,expressed heterologous genes in high levels,and were genetically stable in at least 15 passages.Conclusion rMuV-S79 is a promising platform to accommodate foreign genes like marker genes,other antigens and immunomodulators for addressing various diseases.
文摘In recent years, research that focused on applying 'disarmed' and constructed Tiplasmid of Agrobacterium tumefaciens as a dominant vector for plant genetic engineering has developed quickly. Several vector systems have become especially useful in plant transformation, and a great number of foreign genes have been transferred to dicot plants by means of the leaf-disc transformation method along with the Ti-plasmid vector. Most of the transgenic plants, which bear the novel trait, can accomplish complete regeneration, and the characteristics of the new genotype can be transmitted from generation to generation in the plant cells.
文摘The matrix attachment region (MAR) located downstream of Plastocyanin gene was isolated from the genome of pea. To study the effect of MARs on foreign gene expression in transgenic plants, T DNA vector was constructed in which MARs flanked bothβ glucuronidase(GUS) gene and selectable marker neomycin phosphotransferase (NPT II) gene. The plant expression vectors were transferred into leaf discs via Agrobacterium mediated transformation procedure. The result of GUS measurement showed that pea MAR could increase transgene expression level. The mean expression levels of GUS gene expression in population containing MARs could be increased twofold when compared with that of population without MARs.
基金国家"8 6 3"高技术项目基金资助 (No .2 0 0 1AA2 130 11)上海市现代生物与新药产业发展基金资助 (No .9943190 4)上海市卫生局青年基金资助 (No.0 0 4Y10 )~~
文摘Two transgenic mouse strains , in which the expression of human factor IX (hFIX) in the milk were different significantly, were bred, and the foreign gene integration as well as the content of hFIX in the milk were detected by PCR, Southern blot, FISH and ELISA, respectively. The results showed that approximately 50% offsprings were transgenic positive. Foreign gene integrated in mouse chromosomes was intact. The hFIX expression of each mouse in the same strain was different, the content of hFIX in the milk was (43.32±5.41)μg/mL in FIX-33 transgenic strain and (1.16±0.45)μg/mL in FIX-124 transgenic strain. Meanwhile, the hFIX gene expression between the two strains was different remarkably (P<0.01). We conclude that the characteristics of inheritance and expression in the founder were able to be transferred to their offsprings stably.
