Changes in production of the mating-type-specific glycoproteins, agglutination substances in association with mating type interconversion in homothallic strains of the yeast, Saccharomyces cerevisiae

Summary Sexual activity in homothallic strains of Saccharomyces cerevisiae was investigated. We succeeded in culturing homothallic haploid cells without conjugation, by lowering the pH value of the culture medium. In spore cultures of a homothallic strain both a and pheromones were detected. Agglutination substances of a and mating types were detected in homothallic haploid cells from spore cultures in early logarithmic phase regardless of mating type information at the HML and HMR loci, but either a or agglutination substance was detected predominantly in homothallic haploid cells from spore culture in late logarithmic phase, depending on mating type information at the HML and HMR loci.A part of this work was supported by Grants-in-Aid from Ministry of Education, Science and Culture, Japan, to N.Y.