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2.
Indian J Exp Biol ; 2002 Mar; 40(3): 329-33
Artículo en Inglés | IMSEAR | ID: sea-61798

RESUMEN

The effect of growth regulators and culture conditions on the morphogenetic response of cotyledonary leaf discs was studied in popular cucumber variety (Cucumis sativus cv. Sheetal). Organogenesis was induced directly without any intervening callus phase on Murashige and Skoog medium supplemented with different concentrations of benzyladenine and indole propionic acid. Best results (93%) were obtained in the presence of the 4 mg/L benzyladenine and 1 mg/L IPA. The elongated shoots were rooted in basal medium with 1 mg/L indole butyric acid, hardened and transferred to the field conditions. Genetic transformation system has been established for Cucumis sativus cv. Sheetal, plants by infecting cotyledonary explants with Agrobacterium tumefaciens strain LBA4404 carrying binary plasmid pBI121, which contains scorable marker, beta-glucuronidase and selectable marker nptII under the CaMV 35S promoter. Infection was most effective when explants were infected with Agrobacterium for 15 min and co-cultivated for 2 days in the co-cultivation medium. Shoots were regenerated directly from cotyledonary leaf explants in the presence of kanamycin (50 microg/ml) and analysed. Southern blot analysis confirmed that transformation had occurred. This method will allow genetic improvement of this crop by the introduction of agronomically important genes.


Asunto(s)
Aminobutiratos/farmacología , Cucumis sativus/efectos de los fármacos , Ingeniería Genética , Vectores Genéticos , Indoles/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Plantas Modificadas Genéticamente , Agrobacterium tumefaciens/genética , Transformación Genética
3.
Indian J Biochem Biophys ; 1995 Jun; 32(3): 113-8
Artículo en Inglés | IMSEAR | ID: sea-27406

RESUMEN

In the Zajdela Ascitic Hepatoma (ZAH), a rat tumor, high levels of cell surface sialic acid residues are present which masked the immunogenicity of the cells. We have shown here that cell surface sialic acid level goes down rapidly when ZAH cells are put in culture. The reduction in surface sialic acid levels is due to a decrease in sialic acid residues on the major sialylated glycoprotein, gp 120, as well as a decrease in gp 120 polypeptide. The loss of sialic acid from the cultured cells is reduced if the cells are cultured in the presence of cell free ascitic fluid from ZAH tumor.


Asunto(s)
Animales , Líquido Ascítico/fisiopatología , Membrana Celular/metabolismo , Sistema Libre de Células , Femenino , Neoplasias Hepáticas Experimentales/metabolismo , Ácido N-Acetilneuramínico , Ratas , Ácidos Siálicos/metabolismo , Células Tumorales Cultivadas
4.
J Biosci ; 1985 Dec; 9 (3&4): 231-236
Artículo en Inglés | IMSEAR | ID: sea-160498

RESUMEN

A DNA polymerase activity associated with the detergent insoluble cytoskeletal fraction has been identified in dividing and non-dividing rat hepatocytes and a hepatoma (the Zajdela Ascitic Hepatoma). About 35 % of the enzyme is found associated with the cytoskeletal fraction of non-dividing cells as compared to about 3–6 % of the enzyme in dividing cells even though the dividing cells contain larger amounts of the extranuclear enzyme. The properties of the enzyme are similar to those of DNA polymerase-α. It is suggested that the association of the enzyme with the cytoskeletal fraction has functional significance.

5.
J Biosci ; 1983 Jun; 5(2): 107-114
Artículo en Inglés | IMSEAR | ID: sea-160217

RESUMEN

Purified plasma membranes from normal rat liver, a rat hepatoma and a rat hepatic fibrosarcoma have been shown to contain a protein which drastically inhibits avian myeloblastosis virus reverse transcriptase activity. The inhibition is caused by the binding of the protein to the template. The binding and the consequent inhibition of enzyme activity are template-specific; copying of RNA templates is inhibited whilst that of DNA templates remains unaffected. Investigations using different templates suggest that the inhibitory protein has a stronger binding affinity for G, C-rich templates. The inhibitor appears to have a wide distribution in plasma membranes from diverse sources.

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