Figure 10. The single-gene deletion mutations that increase or decrease the intracellular concentration of trehalose alter the extent to which caloric restriction (CR) and lithocholic acid (LCA) prolong yeast chronological lifespan (CLS).

Wild-type (WT), ath1Δ and tps2Δ cells were cultured in the nutrient-rich YP medium initially containing 0.2% glucose (CR conditions) or 2% glucose (non-CR conditions) with or without LCA. (A–C) The concentrations of trehalose in chronologically aging WT and ath1Δ cell cultures grown under CR conditions (A), survival curves of WT and ath1Δ cells cultured under CR or non-CR conditions (B), and the extent to which CR increases the mean and maximum CLS of WT and ath1Δ strains (C) are shown. (D–F) The concentrations of trehalose in chronologically aging WT and ath1Δ cell cultures grown under non-CR conditions with LCA (D), survival curves of WT and ath1Δ cells cultured under non-CR conditions with or without LCA (E), and the extent to which LCA under non-CR conditions increases the mean and maximum CLS of WT and ath1Δ strains (F) are shown. (G–I) The concentrations of trehalose in chronologically aging WT and tps2Δ cell cultures grown under CR conditions (G), survival curves of WT and tps2Δ cells cultured under CR or non-CR conditions (H), and the extent to which CR increases the mean and maximum CLS of WT and tps2Δ strains (I) are shown. (J–L) The concentrations of trehalose in chronologically aging WT and tps2Δ cell cultures grown under non-CR conditions with LCA (J), survival curves of WT and tps2Δ cells cultured under CR conditions without LCA or under non-CR conditions with LCA (K), and the extent to which LCA under non-CR conditions increases the mean and maximum CLS of WT and glc3Δ strains (L) are shown. Data are presented as means ± SEM (n = 3; ^* p < 0.05; ^** p < 0.01; ns, not significant; the p values for comparing the means of two in groups were calculated using an unpaired two-tailed t test as described in Materials and Methods).