Figure 3.

(a) Rapamycin causes unusually high proportion of two-spored asci. Diploid SK-1 cells were incubated in YPD for 24 hr at 30°C with vigorous shaking and then diluted 1:50 into YPA. After 13.5 hr of further incubation, the cells were washed twice with sterile water and resuspended into SPM supplemented with methanol (control), 100 nM FK506 (+ FK506), or 100 nM rapamycin (+ rapamycin) for another 13 hr. Proportions of the different asci were counted (n = 250). The results shown were averaged from three different experiments. (b) The control and FK506- and rapamycin-treated spores under the light microscope (×1,000). (c) Dosage effects of FK506 and rapamycin on sporulation. Diploid SK-1 cells were cultured in YPD and grown to saturation density for 24 hr at 30°C with vigorous shaking. These cells were then diluted 1:50 into YPA. After 13.5 hr of further incubation, the cells were washed twice with sterile water and resuspended into SPM supplemented with 0, 1, 3, 10, 30, 100, 300, 1,000, 3,000, and 10,000 nM FK506 or rapamycin, respectively. After incubation for another 13 hr, the proportion of two-spored asci was counted (n = 250). The results shown were averaged from three different experiments.