Novel Chinese hamster ultraviolet-sensitive mutants for excision repair form complementation groups 9 and 10.
In this paper we demonstrate that the mutants CHO7PV and CHO4PV isolated by us from the CHO-K1 prol- cell line represent two new complementation groups of UV-sensitive excision repair-defective rodent mutants. We have classified the mutant CHO7PV as representative of Group 9 and CHO4PV as representative of Group 10. Cellular and biochemical characterization of these mutants indicates that they are moderately sensitive to a broad spectrum of mutagens (UV and mono- and bifunctional alkylating agents), partially unable to perform UV-induced DNA repair synthesis, and partially defective in the incision step of the DNA excision repair pathway and in the removal of the two main lesions caused by UV [cyclobutane pyrimidine dimers and (6-4) photo-products]. In terms of UV survival and incision, CHO4PV is apparently more defective than CHO7PV (40% and 50% of wild-type survival, respectively, and 55% and 75% of wild-type incision), whereas when repair DNA synthesis and lesion removal are compared, CHO7PV seems to be more severely affected (30% of wild-type unscheduled DNA synthesis in CHO7PV and 60% in CHO4PV). This suggests a subtlety in the relation between removal of these specific lesions and overall repair capacity and survival.
Stefanini
M
M
Istituto di Genetica Biochimica ed Evoluzionistica C.N.R., Pavia, Italy.
Collins
A R
AR
Riboni
R
R
Klaude
M
M
Botta
E
E
Mitchell
D L
DL
Nuzzo
F
F
D000818:Animals; D002460:Cell Line / Q000502:physiology* / Q000528:radiation effects; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics / Q000528:radiation effects*; D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D005816:Genetic Complementation Test; D006822:Hybrid Cells / Q000502:physiology; D009154:Mutation / Q000528:radiation effects; D014466:Ultraviolet Rays
D004247:DNA