Fig. 5.

Long-lived calorically restricted S. pombe show increased stress resistance. (A) Resistance to an oxidizing agent. Aliquots of cells from the SD + 3% glucose culture or the calorically restricted SD + 0.1% glucose culture were taken when cells had reached maximum density, washed with sterile water, and 5 × 10⁶ cells were resuspended in varying concentrations of H₂O₂ and incubated at 30°C for 90 min. After washing the cells in water, 10-fold serial dilutions were made and 5 μl aliquots of each suspension were spotted onto rich medium where all cells can grow. (B) Resistance to heat stress. Cells grown in normal or calorically restricted condition as in A were heat shocked at 55°C for different lengths of time, placed on ice for 2 min and then diluted and spotted on plates. Fold differences in resistance for the assays in panels A and B were determined by counting the number of single colonies in the most dilute spots in the treated and untreated samples.