title: Phenotypic and epistatic grouping of hypo- and hyper-rec mus mutants in Aspergillus.
abstract: The mutants musK to musS of Aspergillus nidulans are sensitive to methyl-methanesulfonate (MMS) and several of them are meiotic-defective and alter mitotic recombination frequencies. All were found to be cross-sensitive to 4-nitro-quinoline-N-oxide (4-NQO) but unexpectedly none of them was hypersensitive to gamma-rays and few to UV light. Double mus; uvs mutants were constructed to test for interactions with uvs mutations of the four epistatic groups of Aspergillus, "UvsF", "UvsC", "UvsI", and "UvsB". All meiotic-defective mus mutations caused some lethal interactions, usually with uvsF. None of them showed epistasis with UvsF or UvsB group mutants and one, musO, may represent a new group. Three mus mutations that affect recombination were assigned to the UvsC group, namely musN and K, and also musL which is recombination-defective and closely resembles uvsC. While uvsC mutants are mutators and lack UV-mutagenesis, most mus mutants had no effects on mutation. Only musR, which appeared epistatic with uvsI, showed reduced UV-reversion frequencies similar to uvsI. The recombination-proficient mus mutants appeared to be epistatic with more than one group, but in several cases sensitivities were slight and overlaps insufficient to obtain corroborating results with MMS and 4-NQO.
authors.affiliation: Department of Biology, McGill University, Montreal, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Kafer
authors.forename: S K
authors.initials: SK
authors.lastname: Chae
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D001233:Aspergillus nidulans / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D004260:DNA Repair / Q000235:genetics; D004271:DNA, Fungal / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D004352:Drug Resistance, Microbial / Q000235:genetics; D004843:Epistasis, Genetic; D005720:Gamma Rays; D005800:Genes, Fungal; D008540:Meiosis / Q000235:genetics; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D016296:Mutagenesis; D010641:Phenotype; D011836:Radiation Tolerance / Q000235:genetics; D011995:Recombination, Genetic; D014466:Ultraviolet Rays
chemical_list: D004271:DNA, Fungal; D015112:4-Nitroquinoline-1-oxide; D008741:Methyl Methanesulfonate