Abstract
Clones resistant to the cytotoxic action of α-amanitin have been isolated from a strain of fetal human lung diploid fibroblasts. Resistant clones were recovered at a frequency of 5×10−8 after single-step selections following mutagenesis with the mutagen ethyl methane sulfonate. Following propagation in drug-free medium, the clones retained the selected phenotype and in both growth and plating experiments showed a 10–50-fold higher resistance than wild-type cells to the cytotoxicity of 0.25 μg/ml α-amanitin. The α-amanitin sensitivity of RNA polymerase II purified from the mutant cells suggests the presence of two forms of the enzyme, one similar to that found in wild-type cells and a second form with increased resistance to α-amanitin inhibition. These results are consistent with previous evidence that α-amanitin resistance behaves as a codominant marker in mammalian cells.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature cited
Albertini, R. A., and DeMars, R. (1973).Mutat. Res. 18:199–224.
DeMars, R., and Held, K. R. (1972).Humangenetik 16:87–109.
van Zeeland, A. A., van Diggelen, M. C. E., and Simons, J. W. I. M. (1972).Mutat. Res. 14:355–363.
Rappaport, H., and DeMars, R. (1973).Genetics 75:335–345.
Mankovitz, R., Buchwald, M., and Baker, R. M. (1974).Cell 3:221–226.
Chan, V. L., Whitmore, G. F., and Siminovitch, L. (1972).Proc. Natl. Aca. Sci. USA 69:3119–3123.
Somers, D. G., Pearson, M. L., and Ingles, C. J. (1975).J. Biol. Chem. 250:4825–4831.
Amati, P., Blasi, F., Di Porzio, V., Riccio, A., and Traboni, C. (1975).Proc. Natl. Aca. Sci. USA 72:753–757.
Lobban, P. E., and Siminovitch, L. (1975).Cell 4:167–172.
Stanners, C. P., Eliceiri, G. L., and Green, H. (1971).Nature (London), New Biol. 230:52–54.
Cochet-Meilhac, M., and Chambon, P. (1974).Biochim. Biophys. Acta 353:160–184.
Hayflick, L. (1965).Exp. Cell Res. 37:614–636.
Ingles, C. J., Beatty, B. G., Guialas, A., Pearson, M. L., Crerar, M. M., Lobban, P. E., Siminovitch, L., Somers, D. G., and Buchwald, M. (1976). In the Cold Spring Harbor Monograph,RNA Polymerase, (eds.) Chamberlain M. and Losick R. (Cold Spring Harbor Laboratory Publications, Cold Spring Harbor, New York) in press.
Somers, D. G., Pearson, M. L., and Ingles, C. J. (1975).Nature 253:372–374.
Guialis, A., Beatty, B. G., and Ingles, C. J. (1976). In preparation.
Ingles, C. J., Guialis, A., Lam, J., and Siminovitch, L. (1976).J. Biol. Chem. in press.
Crerar, M. M., Andrews, S. J., David, E. S., Somers, D. G., Mandel, J. L., and Pearson, M. L. (1976). In preparation.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Buchwald, M., Ingles, C.J. Human diploid fibroblast mutants with altered RNA polymerase II. Somat Cell Mol Genet 2, 225–233 (1976). https://doi.org/10.1007/BF01538961
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01538961