Survival of Caenorhabditis elegans on agar cultures with and without oxaloacetate supplementation. (A–D) Survival curves of control (N2) and mutant [sir-2.1 (ok434), daf-16 (mgDf50), aak-2 (ok524)] worms. The curves represent the means of the survival curves from the individual experiments. (A) Increased lifespan due to 8 mm oxaloacetate in control worms. (B) Increased lifespan due to 8 mm oxaloacetate in sir-2.1 mutant worms (data from N2 worms tested in the same experiments are also shown). (C) Increased lifespan due to 8 mm oxaloacetate is blocked in FOXO mutant daf-16 worms (data from N2 worms tested in the same experiments are also shown). (D) Increased lifespan due to 8 mm oxaloacetate is blocked in AMP-activated protein kinase mutant aak-2 worms (data from N2 worms tested in the same experiments are also shown). (E) Bar graph showing the change in median lifespan in response to 8 mm oxaloacetate (relative to the same strain grown without oxaloacetate). The change shown by each bar is the mean of the medians measured from all repeats of each experiment ± SEM (shown as error bars), where n = number of repeats for a given experiment. This graph illustrates some of the data shown in Table 1, where data on maximal lifespan and the results of statistical analyses are also given. **P < 0.001, *P < 0.01, by log rank test.