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
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
A DNA fragment containing consensus sequence of matrix attachment region (MAR) has been isolated from pea genome. Compared with original DNA sequence, one 115 bp-long repeat sequence is deleted in the obtained DNA seq...A DNA fragment containing consensus sequence of matrix attachment region (MAR) has been isolated from pea genome. Compared with original DNA sequence, one 115 bp-long repeat sequence is deleted in the obtained DNA sequence. DNA fragments located upstream and down-stream of repeat DNA sequence respectively share 84% and 93% homology to the corresponding original sequence, and contain A-box or T-box and TATAA sequence, which is characteristics short sequence of MARs. To test the function of the DNA sequence, the plant expression vectors in which b-glucuronidase gene (GUS, uidA) was used as reporter gene were constructed and transferred into tobaccos via Agrobacterium-mediated transformation procedure. Quantitative GUS assay showed that the average level of uidA expression was increased twofold for the presence of MAR, and the highest level of GUS activity of transgenic plants could be increased six times. The results cited above suggest that the isolated DNA sequence contains consensus sequence of MARs and has capability to increase expression level of gene in transgenic plants.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the National High Science and Technology Program, National NaturalScience Foundation of China (Grant Nos. 39989001 & 39880023), and National Special Program for Research and Industrialization of Transgenic Plants.
文摘A DNA fragment containing consensus sequence of matrix attachment region (MAR) has been isolated from pea genome. Compared with original DNA sequence, one 115 bp-long repeat sequence is deleted in the obtained DNA sequence. DNA fragments located upstream and down-stream of repeat DNA sequence respectively share 84% and 93% homology to the corresponding original sequence, and contain A-box or T-box and TATAA sequence, which is characteristics short sequence of MARs. To test the function of the DNA sequence, the plant expression vectors in which b-glucuronidase gene (GUS, uidA) was used as reporter gene were constructed and transferred into tobaccos via Agrobacterium-mediated transformation procedure. Quantitative GUS assay showed that the average level of uidA expression was increased twofold for the presence of MAR, and the highest level of GUS activity of transgenic plants could be increased six times. The results cited above suggest that the isolated DNA sequence contains consensus sequence of MARs and has capability to increase expression level of gene in transgenic plants.
