W-mutagenesis in competent cells of Bacillus subtilis.
The relative yield (Nm/N) of fluorescent mutants Ind- after the transformation of Bacillus subtilis cells by means of UV-irradiated DNA is much higher in an uvr- recipient than in an uvr+ strain, when compared at equal fluence, but practically identical at equal survival. Ind- mutations are induced by UV-irradiation of separated single strands of transforming DNA. The H-strand is much more sensitive to the mutagenic action of UV light. Preliminary irradiation of competent recipient cells by moderate UV fluences increases the survival of UV- or gamma-irradiated transforming DNA (W-reactivation) and the frequency of Ind- mutations (W-mutagenesis). During transfection of B. subtilis cells by UV-irradiated prophage DNA isolated from lysogenic cells B. subtilis (phi 105 c+) c-mutants of the phage are obtained in high yield only in conditions of W-mutagenesis, i.e. in UV-irradiated recipient cells. These data show that there is no substantial spontaneous induction of error-prone SOS-repair system in the competent cells of B. subtilis.
D001412:Bacillus subtilis / Q000235:genetics*; D004260:DNA Repair / Q000528:radiation effects*; D004269:DNA, Bacterial / Q000528:radiation effects*; D005720:Gamma Rays; D009154:Mutation; D014162:Transfection / Q000528:radiation effects; D014169:Transformation, Bacterial / Q000528:radiation effects; D014466:Ultraviolet Rays
D004269:DNA, Bacterial