The induction of mutants at the heterozygous tk locus by X radiation was found to be dose-rate dependent in L5178Y-R16 (LY-R16) cells, but very little dose-rate dependence was observed in the case of strain L5178Y-S1 (LY-S1), which is deficient in the repair of DNA double-strand breaks. Induction of mutants by X radiation at the hemizygous hprt locus was dose-rate independent for both strains. These results are in agreement with the hypothesis that the majority of|${\rm X}\text{-radiation-induced}\ {\rm TK}^{-/-}$| mutants harbor multilocus deletions caused by the interaction of damaged DNA sites. Repair of DNA lesions during low-dose-rate X irradiation would be expected to reduce the probability of lesion interaction. The results suggest that in contrast to the|${\rm TK}^{-/-}$| mutants, the majority of mutations at the hprt locus in these strains of L5178Y cells are caused by single lesions subject to dose-rate-independent repair. The vast majority of the|${\rm TK}^{-/-}$| mutants of strain LY-R16 showed loss of the entire active tk allele, whether the mutants arose spontaneously or were induced by high-dose-rate or low-dose-rate X irradiation. The proportion of|${\rm TK}^{-/-}$| mutants with multilocus deletions (in which the products of both the tk gene and the closely linked gk gene were inactivated) was higher in the repair-deficient strain LY-S1 than in strain LY-R16. However, even though the mutant frequency decreased with dose rate, the proportion of mutants showing inactivation of both the tk and gk genes increased with a decrease in dose rate. The reason for these apparently conflicting results concerning the effect of DNA repair on the induction of extended lesions is under investigation.
Skip Nav Destination
Article navigation
June 1990
Research Article|
June 01 1990
The Effect of Dose Rate on X-Radiation-Induced Mutant Frequency and the Nature of DNA Lesions in Mouse Lymphoma L5178Y Cells Available to Purchase
Radiat Res (1990) 122 (3): 316–325.
Citation
Helen H. Evans, Mark Nielsen, Jaroslav Mencl, Min-Fen Horng, Marlene Ricanati; The Effect of Dose Rate on X-Radiation-Induced Mutant Frequency and the Nature of DNA Lesions in Mouse Lymphoma L5178Y Cells. Radiat Res 1 June 1990; 122 (3): 316–325. doi: https://doi.org/10.2307/3577762
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionCiting articles via
Dosimetry: Was and Is an Absolute Requirement for Quality Radiation Research
Daniel Johnson, H. Harold Li, Bruce F. Kimler
Hepatic Stellate Cell-mediated Increase in CCL5 Chemokine Expression after X-ray Irradiation Determined In Vitro and In Vivo
Masataka Taga, Kengo Yoshida, Shiho Yano, Keiko Takahashi, Seishi Kyoizumi, Megumi Sasatani, Keiji Suzuki, Tomohiro Ogawa, Yoichiro Kusunoki, Tatsuaki Tsuruyama
Brain Damage and Patterns of Neurovascular Disorder after Ionizing Irradiation. Complications in Radiotherapy and Radiation Combined Injury
Nikolai V. Gorbunov, Juliann G. Kiang
Lethality Assessments for Acutely Irradiated Cynomolgus Macaques Under Subject-based Care
Issa Melendez-Miranda, Oluseyi O. Fatanmi, Stephen Y. Wise, Sarah A. Petrus, Alana D. Carpenter, Cara Olsen, Artur A. Serebrenik, Luis A. Lugo-Roman, Thomas M. Seed, Michael D. Kaytor, Vijay K. Singh
Radiofrequency Fields and Calcium Movements Into and Out of Cells
Andrew Wood, Ken Karipidis