ISSN:
1365-2958
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
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 Δpre-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 Gα subunit, GNA-1, and the Gβ protein, GNB-1, are essential for female fertility in N. crassa. Trichogynes of Δgna-1 and Δgnb-1 mutants displayed severe defects in growth towards and fusion with male cells, similar to that of Δpre-1 mat A strains. However, the female sterility defect of the Δpre-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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2958.2004.04096.x
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