Figure 1. sDR: a novel dietary restriction method in C. elegans.

(A) Description of our dietary restriction method (sDR) in C. elegans. Populations of worms obtained by synchronized egg laying (EL) were scored and switched to freshly seeded plates every other day (*). sDR was initiated at day 4 of adulthood. (B) Representative pictures of worms fed different concentrations of bacteria expressing DsRed, a red fluorescent protein. Right panel: quantification of DsRed fluorescence of wild type (N2) worms incubated with different bacterial dilutions. Results represent the average and SEM of 3 independent experiments performed with 30 worms per condition at day 7. ***: p<0.001 in one way ANOVA. (C) Serial dilution of OP50-1 bacteria increases worm lifespan (5×10⁸ bacteria/ml= 28.9% increase over 5×10¹¹ bacteria/ml). Mean and standard errors for this experiment done in triplicate are presented in Table S1A. (D) Gompertz analysis shows that sDR decreases the worm mortality rate. (E) sDR treated worms displayed a 36% increase in survival compared with AL-fed worms at 200 mM Paraquat (p<0.0001). The mean and SEM for duplicate experiments done in sextuplicate is presented in Table S1B. (F) sDR delays the age-dependent decline in worm locomotor activity. Quantification of the length of worm tracks after one hour on fresh ad libitum lawns of OP50-1 bacteria was performed with Image J. Each point represents the average movement of at least 20 worms. *: p<0.05; **: p<0.01; ***: p<0.001 in one way ANOVA. (G) sDR induced by dilution of UV-killed bacteria results in a 15.9% increase in lifespan of N2 worms (statistically different from ad libitum fed worms with a p=0.0004). The mean and SEM of two independent experiments conducted in triplicate is presented in Table S1C.