HYBRIDIZATION OF HAMSTER CELLS WITH HIGH AND LOW FOLATE REDUCTASE ACTIVITY
- 1 January 1969
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 62 (1), 88-95
- https://doi.org/10.1073/pnas.62.1.88
Abstract
These studies concern the question whether diffusible repressors control the syntheses of enzymes in mammalian cells. First, clonal sublines of baby hamster kidney (BHK 21/13) cells in culture were selected in stepwise fashion for resistance to aminopterin. These sublines survived in concentrations of aminopterin that were up to 10(4) times higher than those tolerated by wild-type cells because they contained up to 125 times as much folate reductase, probably due to overproduction of the enzyme. When five resistant sublines were hybridized to wild-type lines, 32 of 35 hybrid clones contained intermediate levels of reductase activity. This suggests that overproduction of reductase is not due to loss of a diffusible repressor.Keywords
This publication has 20 references indexed in Scilit:
- Repeated Sequences in DNAScience, 1968
- Regulation of melanin synthesis in mammalian cells, as studied by somatic hybridization. II. The level of regulation of 3,4-dihydroxyphenylalanine oxidase.Proceedings of the National Academy of Sciences, 1968
- Hybridization of somatic cells derived from mouse and Syrian hamster: Evolution of karyotype and enzyme studiesBiochemical Genetics, 1968
- Increase of dihydrofolate reductase activity in cultured mammalian cells after exposure to methotrexate.Proceedings of the National Academy of Sciences, 1967
- RETENTION OF MULTIPLE DEVELOPMENTAL POTENTIALITIES BY CELLS OF A MOUSE TESTICULAR TERATOCARCINOMA DURING PROLONGED CULTURE in vitro AND THEIR EXTINCTION UPON HYBRIDIZATION WITH CELLS OF PERMANENT LINESProceedings of the National Academy of Sciences, 1967
- RESPONSES OF ACETYLCHOLINESTERASE FROM TORPEDO MARMORATA TO SALTS AND CURARIZING DRUGS1966
- Synthesis of collagen and hyaluronic acid by fibroblast hybrids.Proceedings of the National Academy of Sciences, 1966
- Recognition of ribosomal RNA sites in DNA. II. The HeLa cell system.Proceedings of the National Academy of Sciences, 1965
- Genetic regulatory mechanisms in the synthesis of proteinsJournal of Molecular Biology, 1961
- Relation of Folic Acid Reductase to Amethopterin Resistance in Cultured Mammalian CellsJournal of Biological Chemistry, 1961