Abstract
In previous work1, several methotrexate (MTX)-resistant variants were isolated frm the human cell line HeLa BU25, which exhibited a high degree of dihydrofolate (DHFR) gene amplification (estimated to be 250- to 300-fold)1,2. These variants did not contain any chromosome with a homogeneously staining region (HSR) and exhibited only a small average number of minute chromosomes per cell: these two types of karyotypic abnormalities generally accompany selective gene amplification3. We now report that structures containing amplified DHFR genes in one of these variants (HeLa BU25-10B3) can be isolated by pulsed-field gradient or field-inversion gel electrophoresis as homogeneous DNA molecules of ∼650 kilobases (kb). Electron microscopy of metaphase spreads from these cells reveals chromatin fibres with a similar DNA content, which are probably related to the above elements. These represent a novel type of extrachromosomal structures in mammalian cells.
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References
Masters, J., Keeley, B., Gay, H. & Attardi, G. Molec. cell. Biol. 2, 498–507 (1982).
Morandi, C., Masters, J. N., Mottes, M. & Attardi, G. J. molec. Biol. 156, 583–607 (1982).
Stark, G. R. & Wahl, G. M. A. Rev. Biochem. 53, 447–491 (1984).
Maurer, B. J., Barker, P. E., Masters, J. N., Ruddle, F. H. & Attardi, G. Proc. natn. Acad. Sci. U.S.A 81, 1484–1488 (1984).
Human Gene Mapping 8 (1985): Eighth International Workshop on Human Gene Mapping. Cytogenet. Cell Genet. 40, Nos. 1–4 (1985).
Schwartz, D. C. & Cantor, C. R. Cell 37, 67–75 (1984).
Carle, G. F. & Olson, M. V. Nucleic Acids Res. 12, 5647–5664 (1984).
Carle, G. F., Frank, M. & Olson, M. V. Science 232, 65–68 (1986).
Carle, G. F. & Olson, M. V. Proc. natn. Acad. Sci U.S.A. 82, 3756–3760 (1985).
Van der Ploeg, L. H. T., Schwartz, D. C., Cantor, C. R. & Borst, P. Cell 37, 77–84 (1984).
Kemp, D. J. et al. Nature 315, 347–350 (1985).
Garvey, E. P. & Santi, D. V. Science 233, 535–540 (1986).
Hamkalo, B. A., Farnham, P. J., Johnston, R. & Schimke, R. T. Proc. natn. Acad. Sci. U.S.A. 82, 1126–1130 (1985).
Finch, J. T. & Klug, A. Proc. natn. Acad. Sci. U.S.A. 73, 1897–1901 (1976).
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Maurer, B., Lai, E., Hamkalo, B. et al. Novel submicroscopic extrachromosomal elements containing amplified genes in human cells. Nature 327, 434–437 (1987). https://doi.org/10.1038/327434a0
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DOI: https://doi.org/10.1038/327434a0
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