title: Sensitivity to bleomycin and hydrogen peroxide of DNA repair-defective mutants in Neurospora crassa.
abstract: Mutations were induced in Neurospora which cause increased sensitivity to MMS (methyl methane-sulfonate) and other mutagens. Genetic analysis of such mus demonstrated that some of them defined new DNA repair genes (mus-21, and mus-27 to mus-30), while others represented new alleles in previously known genes. To characterize them further, and especially to identify rec- types which have not yet been found in this species, many MMS-sensitive strains were tested for cross-sensitivities to bleomycin (BLM) and to hydrogen peroxide (H2O2) to which some rec- of other species are hypersensitive. In Neurospora, many of the MMS-sensitive mutants were found to be cross-sensitive to BLM and frequently these were also hypersensitive to ionizing radiation. Bleomycin sensitivity was demonstrated for all alleles of 10 different genes, 4 of them new ones, with mus-27 being the most sensitive of the latter (resembling uvs-6; Koga and Schroeder, 1987, Mutation Res., 183, 139). In contrast, very few of the MMS-sensitive mutants were hypersensitive to H2O2 and, in general, results of H2O2 tests were variable and differences between strains small. However, consistent deviations from wild type were observed in a few cases (most clearly for mus-9 and mus-11) when results from treatments of germinating conidia were compared with those of non-growing ones.
authors: Biology Department, McGill University, Montreal, Canada.
authors: E
authors: E
authors: Käfer
authors: D
authors: D
authors: Luk
mesh_terms: D001761:Bleomycin / Q000494:pharmacology*; D004260:DNA Repair; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009154:Mutation; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000235:genetics*
chemical_list: D001761:Bleomycin; D006861:Hydrogen Peroxide