Isolation of Chinese hamster cell mutants deficient in dihydrofolate reductase activity.
- 1 July 1980
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 77 (7), 4216-4220
- https://doi.org/10.1073/pnas.77.7.4216
Abstract
Mutants of Chinese hamster ovary cells lacking dihydrofolate reductase (tetrahydrofolate dehydrogenase, 7,8-dihydrofolate:NADP+ oxidoreductase; EC 1.5.1.3) activity were isolated after mutagenesis and exposure to high-specific-activity [3H]deoxyuridine as a selective agent. Fully deficient mutants could not be isolated starting with wild-type cells, but could readily be selected from a putative heterozygote that contains half of the wild-type level of dihydrofolate reductase activity. The heterozygote was selected from wild-type cells using [3H]deoxyuridine together with methotrexate to reduce intracellular dihydrofolate reductase activity. Fully deficient mutants require glycine, a purine and thymidine for growth; this phenotype is recessive to wild type in cell hybrids. Revertants were isolated, one of which produces a heat-labile dihydrofolate reductase activity. These mutants may be useful for metabolic studies relating to cancer chemotherapy and for fine-structure genetic mapping of mutations by using available molecular probes for this gene.This publication has 34 references indexed in Scilit:
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