title: Characterization of mat A-2, mat A-3 and deltamatA mating-type mutants of Neurospora crassa.
abstract: The mating-type locus of Neurospora crassa regulates mating identity and entry into the sexual cycle. The mat A idiomorph encodes three genes, mat A-1, mat A-2, and mat A-3. Mutations in mat A-1 result in strains that have lost mating identity and vegetative incompatibility with mat a strains. A strain containing mutations in both mat A-2 and mat A-3 is able to mate, but forms few ascospores. In this study, we describe the isolation and characterization of a mutant deleted for mat (deltamatA), as well as mutants in either mat A-2 or mat A-3. The deltamatA strain is morphologically wild type during vegetative growth, but it is sterile and heterokaryon compatible with both mat A and mat a strains. The mat A-2 and mat A-3 mutants are also normal during vegetative growth, mate as a mat A strain, and produce abundant biparental asci in crosses with mat a, and are thus indistinguishable from a wild-type mat A strain. These data and the fact that the mat A-2 mat A-3 double mutant makes few asci with ascospores indicate that MAT A-2 and MAT A-3 are redundant and may function in the same pathway. Analysis of the expression of two genes (sdv-1 and sdv-4) in the various mat mutants suggests that the mat A polypeptides function in concert to regulate the expression of some sexual development genes.
authors.affiliation: Department of Botany, The University of British Columbia, Vancouver, Canada.
authors.forename: A V
authors.initials: AV
authors.lastname: Ferreira
authors.forename: Z
authors.initials: Z
authors.lastname: An
authors.forename: R L
authors.initials: RL
authors.lastname: Metzenberg
authors.forename: N L
authors.initials: NL
authors.lastname: Glass
mesh_terms: D001483:Base Sequence; D018076:DNA, Complementary; D004271:DNA, Fungal; D004268:DNA-Binding Proteins / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics*; D017353:Gene Deletion; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D009492:Neurospora crassa / Q000235:genetics*; D010641:Phenotype
chemical_list: D018076:DNA, Complementary; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C097997:MTA-1 protein, Neurospora crassa; C099382:MTA-2 protein, Neurospora crassa; C099383:MTA-3 protein, Neurospora crassa