Factors affecting pheromone induction of Schizosaccharomyces pombe and isolation of pheromone induction mutants

The mating pheromones of Schizosaccharomyces pombe are induced by nutritional starvation. However, this nutritional signaling pathway is largely unknown. For a complete understanding of pheromone induction, we examined the environmental factors affecting the induction after cells were transferred to a nitrogen-starved medium. It appeared that the induction of mfm2 transcription was affected by the general environmental stress including incubation time, incubation temperature, and the growth phase of the cells. We identified 7 pheromone induction mutants by screening temperature sensitive mutant bank. Three of these mutants showed elongated cell shapes and one mutant exhibited swollen cell morphology in permissive culture, suggesting that their cell cycles were also impaired. Characterization of the pheromone induction mutants may elucidate the components required in nutritional signaling pathway leading to pheromone induction.