Figure 1.

(a) Rapamycin causes an increase in sporulation efficiency in BR2495 cells. Diploid yeast BR2495 cells were grown to saturation in YPD medium for 24 hr at 30°C with vigorous shaking. These cells were added to YPA medium at a 1:50 dilution and incubated for a further 13.5 hr at 30°C. The cells were then pelleted, washed twice with sterile water, resuspended into SPM with or without rapamycin or FK506, and incubated for another 36 hr. Different asci were counted under the phase-contrast light microscope. The results from three different experiments were averaged (n = 250). Control, methanol (solvent for both FK506 and rapamycin); FK506, 100 nM final concentration; rapamycin, 100 nM final concentration. (b) Increased dyad population in the presence of rapmycin. The same samples were counted for proportions of different ascospores. The percentage of single-spored asci (monads) was very low (<1%) and omitted from the results. A small percentage of three-spored asci (triads) were counted as four-spored asci (tetrads) in this analysis. The results show an average of three different experiments (n = 250).