Responses of 4 X-ray-sensitive CHO cell mutants to different radiations and to irradiation conditions promoting cellular recovery
Thacker, J.; Stretch, A.
Mutation Research 146(1): 99-108
1985
ISSN/ISBN: 0027-5107 PMID: 4000151 Document Number: 245201
Four X-ray-sensitive mutants of CHO cells, described previously by Jeggo and Kemp showed enhanced sensitivity to both 60Co .gamma.-rays and 238Pu .alpha.-particles relative to the responses of the parent line. The enhanced response to a densely ionizing radiation (.alpha.-particles) was less than that to X- or .gamma.-rays, suggesting that these mutants are deficient mainly in the repair of damage from relatively sparsely ionizing radiation tracks. Plateau-phase cultures of the parental CHO cells showed considerable recovery upon irradiation with low-dose-rate .gamma.-rays, compared to irradiation at high dose rates, but little or no recovery was seen for the mutants. Preliminary data on recovery during post-irradiation holding of plateau-phase cultures show that this process is also absent in the mutants. These responses have several similarities to those of cells from patients with the radiosensitive disorder ataxia telangiectasia (AT), and are discussed with reference to AT cells and other radiosensitive mutants.