PMID: 43600Sep 1, 1979

Isolation and characterization of CHO cell mutants with altered asparagine synthetase

Somatic Cell Genetics
M M Waye, C P Stanners


Two asparagine auxotrophic mutants (N3, N4) were isolated from the Gat- strain of Chinese hamster ovary cells, using a selection procedure modified from that of Goldfarb et al. (1). The defect in these mutants is due to a deficiency in asparagine synthetase activity. N3, in particular, had no measurable enzyme activity. Complementation analysis by PEG-mediated cell fusion showed that the auxotrophic phenotype behaved as a recessive trait; complementation was obtained between N3 or N4 and the pseudoauxotroph, Asn3, which has a temperature-sensitive asparagyl-tRNA synthetase activity. Revertants obtained by plating N3 or N4 in asparagine-free medium had about normal levels of asparagine synthetase activity and were produced with a probability of about 10(-6) per cell per generation. Three particular revertants of N3 and one revertant of N4 were shown to have asparagine synthetase activities that were different in thermolability from that of the wild type. This observation is consistent with the suggestion that N3 and N4 have defective structural genes rather than defective regulatory genes for asparagine synthetase.


Sep 1, 1986·Somatic Cell and Molecular Genetics·M Harris
Sep 1, 1983·Somatic Cell Genetics·S M ArfinM Smith
Jan 1, 1983·Breast Cancer Research and Treatment·J H Goldie
Jan 8, 2000·Cell Adhesion and Communication·J Charbonneau, C P Stanners
Apr 1, 1989·Genomics·Y P ZhangI L Andrulis
Apr 1, 1989·Journal of Cellular Physiology·C E HepferJ J Freed


Jun 1, 1977·Proceedings of the National Academy of Sciences of the United States of America·S M ArfinG W Hatfield
Jan 1, 1975·Advances in Pharmacology and Chemotherapy·D A Cooney, R J Rosenbluth
May 1, 1978·Journal of Cellular Physiology·C P StannersJ L Harkins
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Jan 1, 1967·Annual Review of Microbiology·J Farrell, A Rose
Jun 1, 1971·Journal of Cellular Physiology·J Morrow
Mar 10, 1971·Nature: New Biology·C P StannersH Green
May 3, 1968·Science·B HorowitzE Stockert
Feb 1, 1954·The Journal of Experimental Medicine·R DULBECCO, M VOGT

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Ovarian Diseases
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