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Amplification and Loss of Dihydrofolate Reductase Genes in a Chinese Hamster Ovary Cell Line

Overview
Journal Mol Cell Biol
Specialty Cell Biology
Date 1981 Dec 1
PMID 7346712
Citations 41
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Abstract

During stepwise increases in the methotrexate concentration in culture medium, we selected Chinese hamster ovary cells that contained elevated dihydrofolate reductase levels which were proportional to the number of dihydrofolate reductase gene copies (i.e., gene amplification). We studied the dihydrofolate reductase levels in individual cells that underwent the initial steps of methotrexate resistance by using the fluorescence-activated cell sorter technique. Such cells constituted a heterogeneous population with differing dihydrofolate reductase levels, and they characteristically lost the elevated enzyme levels when they were grown in the absence of methotrexate. The progeny of individual cells with high enzyme levels behaved differently and could lose all or variable numbers of the amplified genes.

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References
1.
Dugaiczyk A, Boyer H, Goodman H . Ligation of EcoRI endonuclease-generated DNA fragments into linear and circular structures. J Mol Biol. 1975; 96(1):171-84. DOI: 10.1016/0022-2836(75)90189-8. View

2.
Kaufman R, BROWN P, Schimke R . Amplified dihydrofolate reductase genes in unstably methotrexate-resistant cells are associated with double minute chromosomes. Proc Natl Acad Sci U S A. 1979; 76(11):5669-73. PMC: 411711. DOI: 10.1073/pnas.76.11.5669. View

3.
Southern E . Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975; 98(3):503-17. DOI: 10.1016/s0022-2836(75)80083-0. View

4.
Biedler J, Spengler B . Metaphase chromosome anomaly: association with drug resistance and cell-specific products. Science. 1976; 191(4223):185-7. DOI: 10.1126/science.942798. View

5.
Alt F, Kellems R, Schimke R . Synthesis and degradation of folate reductase in sensitive and methotrexate-resistant lines of S-180 cells. J Biol Chem. 1976; 251(10):3063-74. View