Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Opine synthases are enzymes produced in dicotyledonous plants as the result of a natural gene transfer phenomenon. Agrobacteria contain Ti plasmids that direct the transfer, stable integration and expression of a number of genes in plants, including the genes coding for octopine or nopaline synthase. This fact was used as the basis for the construction of a number of chimeric genes combining the 5' upstream promoter sequences and most of the untranslated leader sequence of the nopaline synthase (nos) gene with the coding sequence of two bacterial genes: the aminoglycoside phosphotransferase (APH(3')II) gene of Tn5 and the methotrexate-insensitive dihydrofolate reductase (DHFR Mtx) of the R67 plasmid. The APH(3')II enzyme inactivates a number of aminoglycoside antibiotics such as kanamycin, neomycin and G418. Kanamycin, G418 and methotrexate are very toxic to plants. The chimeric NOS-APH(3')II gene, when transferred to tobacco cells using the Ti plasmid as a gene vector, was expressed and conferred resistance to kanamycin to the plant cells. Kanamycin-resistant tobacco cells were shown to contain a typical APH(3')II phosphorylase activity. This chimeric gene can be used as a potent dominant selectable marker in plants. Similar results were also obtained with a NOS-DHFR Mtx gene. Our results demonstrate that foreign genes are not only transferred but are also functionally expressed when the appropriate constructions are made using promoters known to be active in plant cells.
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PMID:Chimeric genes as dominant selectable markers in plant cells. 1645 64

By using npt-gene as assistant selection-marker, treating Japonica rice Zhonghua 9 [ZH9 (CK)] and transferred lysozyme gene rice (the donor rice is Japonica rice Zhonghua 9) [ZH9(R)] with antibiotics, we built a system of quickly testing transgenic rice offspring. Detached leaves of ZH9(R) and ZH9(CK) were treated by Kanamycin (0, 400, 450, 500, 550, 600 and 700 mg/L) and G418 (0, 40, 60, 80, 100, 150 and 200 mg/L) with different concentrations. The result show effect of Kanamycin is not evident and G418 is the best antibiotics to test transgenic rice with npt- gene. The data showed that 80 mg/L G418 (treating 4 d) was optimal to test transgenic rice. Further study was done with seeds, young embryos and seedlings by G418 testing: the alive seeds were cultured in the culture dishes which filled with a series of G418 solution with different concentration of 0, 100, 150, 200, 250, 300 and 350 mg/L; in the tissue culture room, the germinating embryos were inoculated in the culture medium (1/2 MS+0.5 mg/L 6-BA+1.5% sucrose) which contains G418 with 0, 150, 200, 250 and 300 mg/L concentration; the aseptic seedlings were inoculated in the the same culture medium (1/2 MS+0.5 mg/L 6-BA+1.5% sucrose) which contains G418 with 0, 100, 150, 200 and 250 mg/L concentration. The conclusions indicated that 300 mg/L (treating 7 d) was the critical concentration to test seeds of transgenic rice; 200 mg/L (treating 10 d) was the critical concentration to test young embryo of transgenic rice; 150 mg/L (treating 12 d) was the critical concentration to test seedlings of transgenic rice. Two primers were designed based on npt- and lysozyme gene sequences. PCR technology confirmed the above detection system. The preliminary results showed npt-was tightly linked with lysozyme gene. Above confirmed critical concentrations were applied to test detached leaves, seeds, young embryos and seedlings of transferred generations. The effect was very obvious. It is convenient, intuitionistic, and exact way that aparting the positive plants from the mixture of transgenic positive and negative plants with G418.
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PMID:[Quick testing-technology of transgenic rice with npt- screen marker gene]. 1754 15

Lactuca sativa can be routinely transformed using Ti plasmids of Agrobacterium tumefaciens containing a chimeric kanamycin resistance gene (NOS.NPTII.NOS). Critical experimental variables were plant genotype, bacterial concentration, presence of a nurse culture and timing of transfers between tissue culture media. Transformation was confirmed by the ability to callus and root in the presence of kanamycin, nopaline production, and by hybridization in Southern blots. Transformation has been achieved with several Ti vectors. Several hundred transformed plants have been regenerated. Kanamycin resistance was inherited monogenically. Homozygotes can be selected by growing R2 seedlings on media containing G418.
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PMID:Transformation of lettuce (Lactuca sativa) mediated by Agrobacterium tumefaciens. 2424 27