The goal of this project is to understand the molecular mechanisms that control the life cycle of Neurospora crassa. This goal will be approached by testing the hypothesis that regulated expression of genes at the mating type locus controls target genes that effect mating type functions. N. crassa is a haploid eukaryote, the most intensively studied filamentous Ascomycete. The mating type locus of Neurospora controls heterokaryosis during vegetative growth, and mating and morphological development during sexual development. During vegetative growth, the two alleles of mating type, a and A, prevent formation of mixed mating type heterokaryons. However, only opposite mating types mate and undergo sexual reproduction, a multistep process in which the mating type genes play multiple roles. Each allele of mating type contains multiple functional regions required for distinct steps. One region of a encodes a polypeptide (mt a-1) critical to vegetative incompatibility and mating. The sequence of mt a-1 suggests that it is a DNA binding protein. The role of a-2 and the functions of mt a-1 and the identities of genes that interact with it to control the Neurospora life cycle will be investigated by a combined genetic, biochemical, and molecular genetic approach.
