A pheromone receptor gene, pre-1, is essential for mating type-specific directional growth and fusion of trichogynes and female fertility in Neurospora crassa

Mol Microbiol. 2004 Jun;52(6):1781-98. doi: 10.1111/j.1365-2958.2004.04096.x.

Abstract

Neurospora crassa is a heterothallic filamentous fungus with two mating types, mat a and mat A. Its mating involves differentiation of female reproductive structures (protoperithecia) and chemotropic growth of female-specific hyphae (trichogynes) towards a cell of the opposite mating type in a pheromone-mediated process. In this study, we characterize the pre-1 gene, encoding a predicted G-protein-coupled receptor with sequence similarity to fungal pheromone receptors. pre-1 is most highly expressed in mat A strains under mating conditions, but low levels can also be detected in mat a strains. Analysis of pre-1 deletion mutants showed that loss of pre-1 does not greatly affect vegetative growth, heterokaryon formation or male fertility in either mating type. Protoperithecia from Deltapre-1 mat A mutants do not undergo fertilization; this defect largely stems from an inability of their trichogynes to recognize and fuse with mat a cells. Previous work has demonstrated that the Galpha subunit, GNA-1, and the Gbeta protein, GNB-1, are essential for female fertility in N. crassa. Trichogynes of Deltagna-1 and Deltagnb-1 mutants displayed severe defects in growth towards and fusion with male cells, similar to that of Deltapre-1 mat A strains. However, the female sterility defect of the Deltapre-1 mat A mutant could not be complemented by constitutive activation of gna-1, suggesting additional layers of regulation. We propose that PRE-1 is a pheromone receptor coupled to GNA-1 that is essential for the mating of mat A strains as females, consistent with a role in launching the pheromone response pathway in N. crassa.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Fungal Proteins / genetics*
  • Fungal Proteins / physiology
  • GTP-Binding Protein alpha Subunits, Gi-Go / genetics
  • GTP-Binding Protein alpha Subunits, Gi-Go / physiology
  • Gene Deletion
  • Gene Expression Regulation, Fungal
  • Genes, Essential
  • Genes, Fungal*
  • Genes, Mating Type, Fungal*
  • Genetic Complementation Test
  • Mutation
  • Neurospora crassa / genetics*
  • Neurospora crassa / growth & development*
  • Neurospora crassa / physiology
  • Receptors, Pheromone / genetics*
  • Receptors, Pheromone / physiology*

Substances

  • Fungal Proteins
  • GNA-1 protein, Neurospora crassa
  • Receptors, Pheromone
  • GTP-Binding Protein alpha Subunits, Gi-Go