The significance of DNA double-strand breaks in the UV inactivation of yeast cells.
The radiation-sensitive mutant rad 54-3 of Saccharomyces cerevisiae temperature-conditional for the repair of DNA double-strand breaks was exposed to 254 nm ultraviolet radiation and incubated at the restrictive and permissive temperatures. A large difference in survival was seen indicating the involvement of double-strand breaks in cellular inactivation at least in this strain. Pulsed-field gel electrophoresis of DNA showed that double-strand breaks are not directly induced but develop upon incubation under growth conditions. Their number is highest after about 4 h, after 8 h repair is complete in wild-type cells. With the aid of the excision-deficient double mutant rad3rad54 it could be demonstrated that strand break formation proceeds independent of excision repair.
Kiefer
J
J
Strahlenzentrum der Justus-Liebig-Universität, Giessen, Germany.
Feige
M
M
D004249:DNA Damage; D004271:DNA, Fungal / Q000235:genetics* / Q000302:isolation & purification / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000528:radiation effects*; D013696:Temperature; D014466:Ultraviolet Rays
D004271:DNA, Fungal