The Genetic Control of Cell Growth and Development in Yeast Saccharomyces cerevisiae: Disturbed Sporulation in Diploids with a Decreased Activity of the Ras/cAMP Signal Transduction Pathway

Seven haploid strains (four with the MAT mating type and three with the MATa mating type) were selected from the Peterhof genetic collection of yeast. Previous phenotypic analysis assigned six of these strains to a physiological group of strains with changed activity of the Ras/cAMP signal transduction pathway. The haploids were crossed, and the resulting 12 diploids showed higher glycogen accumulation, tolerance to heat shock and nitrogen starvation, and sporulation in complete media. Ten of the diploids expressed the hypersporulation phenotype (higher sporulation efficiency). The phenotypic characters of these ten diploids suggested a reduced activity of the Ras/cAMP pathway. All 12 diploids were tested for sporulation and production of two groups of asci (those with one or two spores and those with three or four spores) as dependent on culture conditions (21, 30, or 34°C; standard sporulation medium or a complete medium containing potassium acetate or glycerol in place of glucose). Sporulation proved to depend on temperature and medium composition. The results are collated with the data on yeast phenotypes associated with a lower activity of the Ras/cAMP signal transduction pathway.