Figure 7. The single-gene deletion mutations that increase or decrease the intracellular glycogen concentration do not affect the efficiency of yeast chronological lifespan (CLS) extension by caloric restriction (CR) or lithocholic acid (LCA).

Wild-type (WT), gph1Δ and glc3Δ 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 glycogen in chronologically aging WT and gph1Δ cell cultures grown under CR conditions (A), survival curves of WT and gph1Δ cells cultured under CR or non-CR conditions (B), and the extent to which CR increases the mean and maximum CLS of WT and gph1Δ strains (C) are shown. (D–F) The concentrations of glycogen in chronologically aging WT and gph1Δ cell cultures grown under non-CR conditions with LCA (D), survival curves of WT and gph1Δ 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 gph1Δ strains (F) are shown. (G–I) The concentrations of glycogen in chronologically aging WT and glc3Δ cell cultures grown under CR conditions (G), survival curves of WT and glc3Δ cells cultured under CR or non-CR conditions (H), and the extent to which CR increases the mean and maximum CLS of WT and glc3Δ strains (I) are shown. (J–L) The concentrations of glycogen in chronologically aging WT and glc3Δ cell cultures grown under non-CR conditions with LCA (J), survival curves of WT and glc3Δ 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).