The DOI matches its Crossref record; 13 of the 13 references it cites were found in a registry or an index.
Amplified dihydrofolate reductase genes are localized to a homogeneously staining region of a single chromosome in a methotrexate-resistant Chinese hamster ovary cell line.
Open accessAbstract
Methotrexate-resistant Chinese hamster ovary cells selected for high resistance by progressive increments of methotrexate in the culture medium have levels of dihydrofolate reductase (tetrahydrofolate dehydrogenase, 7,8-dihydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) 200 times that of sensitive cells and a corresponding increase in the number of copies of the dihydrofolate reductase gene. The resistant cells contain an expanded region on the second chromosome (homogeneously staining region) that is not present in sensitive cells. In situ hybridization of DNA complementary to dihydrofolate reductase mRNA shows that the dihydrofolate reductase genes are specifically localized to the homogeneously staining region of this chromosome in the resistant cells.
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Cites
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Cited by
Isolation of Chinese hamster cell mutants deficient in dihydrofolate reductase activity
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Chromothripsis drives the evolution of gene amplification in cancer
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Metadata
- Authors
- Nunberg, J. H., Kaufman, R. J., Schimke, R. T., Urlaub, G., & Chasin, L. A.
- Venue
- Proceedings of the National Academy of Sciences
- Published
- 1978-11
- Volume
- 75
- Issue
- 11
- Pages
- 5553-5556
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- OpenAlex
- W2066689347
- Cited by
- 364
- References
- 13
- FWCI
- 14.58
- Type
- journal article
- Language
- en
- Open access
- green
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- CoChat. (2026). Citation check: Amplified dihydrofolate reductase genes are localized to a homogeneously staining region of a single chromosome in a methotrexate-resistant Chinese hamster ovary cell line. https://app.cochat.ai/papers/10.1073/pnas.75.11.5553
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- Nunberg, J. H., Kaufman, R. J., Schimke, R. T., Urlaub, G., & Chasin, L. A. (1978). Amplified dihydrofolate reductase genes are localized to a homogeneously staining region of a single chromosome in a methotrexate-resistant Chinese hamster ovary cell line. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.75.11.5553
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