Neurospora crassa fmf-1 encodes the homologue of the Schizosaccharomyces pombe Ste11p regulator of sexual development

摘要

The Neurospora crassa fmf-1 mutation exerts an unusual ‘perithecium-dominant’ developmental arrest; fmf-1 × fmf-1 + cross becomes arrested in perithecial development regardless of whether the mutant participates in the cross as the male or female parent. We localized fmf-1 to the LG IL genome segment between the centromere-proximal breakpoint of the chromosome segment duplication Dp(IL)39311 and the centromere. By mapping crossovers with respect to RFLP markers in this region we further localized fmf-1 to an approximately 34-kb-genome segment. Partial sequencing of this segment revealed a point mutation in the gene NCU 09387.1, a homologue of the Schizosaccharomyces pombe ste11 + regulator of sexual development. The fmf-1 mutation did not complement a NCU 09387.1 deletion mutation, and transformation with wild-type NCU 09387.1 complemented fmf-1. S. pombe Ste11 protein (Ste11p) is a transcription factor required for sexual differentiation and for the expression of genes required for mating pheromone signalling in matP and matM cells. If FMF-1 also plays a corresponding role in mating pheromone signalling in Neurospora, then protoperithecia in an fmf-1 × fmf-1 + cross would be unable to either send or receive sexual differentiation signals and thus become arrested in development. Keywords perithecial development - chromosome segment duplications - mating pheromones - yeast - Neurospora We dedicate this paper to our friend Namboori Bhaskara Raju, Stanford University, to recognize his many quiet, yet very significant, contributions to fungal biology. He continues to be such a fine example for the rest of us.