Isolation of Chinese hamster cell mutants deficient in dihydrofolate reductase activity
Open accessAbstract
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 itself was selected from wild-type cells by 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 have been 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.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The DHFR selection uses CHO cell mutants deficient for DHFR.
“Similarly, the DHFR selection uses the fact that CHO cell mutants have been selected to be deficient for DHFR (Urlaub and Chasin, 1980).”
From Therapeutic glycoprotein production in mammalian cells (2017) · cites this paper as Urlaub and Chasin, 1980
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
Reversion of a Chinese Hamster Cell Auxotrophic Mutant
Chasin, L. A., Feldman, A., Konstam, M., & Urlaub, G. (1974) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.71.3.718 · Cited by 81 · see citing works
Self-citation
Flagged first, then by citations
Research works printed but not linked: 9
- [1]Lehninger, A. L. (1970) Biochemistry (Worth, New York), pp. 543-547.
- [9]Littlefield, J. W. (1969) Proc. Natl. Acad. Sci. USA 62, 88–95.
- [14]Chasin, L. A. & Urlaub, G. (1979) in Banbury Report 2. Mammalian Cell Mutagenesis: The Maturation of Test Systems, eds. Hsie, A., O'Neill, J. P. & McElheny, V. (Cold Spring Harbor Laboratory, Cold Spring Harbor, NY), pp. 201–208.
- [15]Kao, F.-T. & Puck, T. T. (1968) Proc. Natl. Acad. Sci. USA 60, 1275-1281.
- [16]Ham, R. G. (1965) Proc. Natl. Acad. Sci. USA 53, 288–293.
- [26]Chasin, L. A., Feldman, A., Konstam, M. & Urlaub, G. (1974) Proc. Natl. Acad. Sci USA 71, 718–722.
- [25]Kao, F. T., Chasin, L. A. & Puck, T. T. (1969) Proc. Natl. Acad. Sci. USA 64, 1284–1291.
- [31]Nunberg, J. H., Kaufman, R. J., Schimke, R. T., Urlaub, G. & Chasin, L. A. (1978) Proc. Natl. Acad. Sci. USA 75, 5553– 5556.
- [33]Siciliano, M. J., Siciliano, J. & Humphrey, R. M. (1978) Proc. Natl. Acad. Sci. USA 75, 1919–1923.
Cited by
Sorted by citations
Kanda, Y., Yamada, T., Mori, K., Okazaki, A., Inoue, M., Kitajima-Miyama, K., Kuni-Kamochi, R., Nakano, R., Yano, K., Kakita, S., et al. (2007) · Glycobiology · doi:10.1093/glycob/cwl057 · Cited by 372 · see citing works
Therapeutic glycoprotein production in mammalian cells
Lalonde, M.-E., & Durocher, Y. (2017) · Journal of Biotechnology · doi:10.1016/j.jbiotec.2017.04.028 · Cited by 296 · see citing works
Biochemical, immunological, and in vivo functional characterization of B-domain-deleted factor VIII
Pittman, D., Alderman, E., Tomkinson, K., Wang, J., Giles, A., & Kaufman, R. (1993) · Blood · doi:10.1182/blood.v81.11.2925.2925 · Cited by 268 · see citing works
CO2 in large-scale and high-density CHO cell perfusion culture
Gray, D. R., Chen, S., Howarth, W., Inlow, D., & Maiorella, B. L. (1996) · Cytotechnology · doi:10.1007/bf00353925 · Cited by 176 · see citing works
Feeding lactate for CHO cell culture processes: Impact on culture metabolism and performance
Li, J., Wong, C. L., Vijayasankaran, N., Hudson, T., & Amanullah, A. (2012) · Biotechnology and Bioengineering · doi:10.1002/bit.24389 · Cited by 137 · see citing works
Stolfa, G., Smonskey, M. T., Boniface, R., Hachmann, A., Gulde, P., Joshi, A. D., Pierce, A. P., Jacobia, S. J., & Campbell, A. (2018) · Biotechnology Journal · doi:10.1002/biot.201700227 · Cited by 97 · see citing works
Ohya, T., Hayashi, T., Kiyama, E., Nishii, H., Miki, H., Kobayashi, K., Honda, K., Omasa, T., & Ohtake, H. (2008) · Biotechnology and Bioengineering · doi:10.1002/bit.21758 · Cited by 96 · see citing works
Gal, C. S.-L., Raufaste, D., Derick, S., Blankenstein, J., Allen, J., Pouzet, B., Pascal, M., Wagnon, J., & Ventura, M. A. (2007) · American Journal of Physiology-Regulatory, Integrative and Comparative Physiology · doi:10.1152/ajpregu.00062.2007 · Cited by 35 · see citing works
- Authors
- Urlaub, G., & Chasin, L. A.
- Affiliations
- Columbia University (US)
- ORCID
- Chasin, L A
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 1980-07
- Volume
- 77
- Issue
- 7
- Pages
- 4216-4220
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC349802
- OpenAlex
- W1976492411
- Cited by
- 876
- References
- 1
- Citations by year
- 2026: 3 · 2025: 6 · 2024: 8 · 2023: 5 · 2022: 8 · 2021: 9 · 2020: 9 · 2019: 14 · 2018: 12 · 2017: 12 · 2016: 15 · 2015: 19 · 2014: 17 · 2013: 27 · 2012: 12
- FWCI
- 5.31
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Molecular Research
- Health Sciences › Medicine › Rheumatology › Folate and B Vitamins Research
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Carcinogens and Genotoxicity Assessment
- Keywords
- dihydrofolate reductase, CHO cells, mutant isolation, methotrexate, revertants, heat-labile enzyme, gene mapping, cancer chemotherapy, folate metabolism
- MeSH terms
- Animals, Cell Line, Cricetulus, Female, Cricetinae, Heterozygote, Hybrid Cells, Mutation, Ovary, Selection, Genetic, Tetrahydrofolate Dehydrogenase
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
