Figure 5: Dosage effects on the lifespan C. briggsae with select positive chemicals.

(a–c) Dose response effects on the median lifespan of select C. briggsae strains after treatment with chemicals that exhibited strong positive effects on the C. elegans strains. Dosing was performed only on strains that failed to respond positively in the initial tests (single dose experiments), as we did not attempt to identify peak responses, instead we only sought to identify whether positive effects could be obtained by altering doses. Chemical doses were chosen to center around the effective dose identified for C. elegans strains and were sometimes expanded after preliminary rounds of testing. ThT exhibited a positive effect on strain JU1348 at 25 μM, but was profoundly toxic to all strains at and above 100 μM (a). NP1 exhibited a positive effect on AF16 and JU1348 at 10 μM relative to control treated populations and showed reduced toxicity to HK104 at low micromolar concentrations (b). αKG did not exhibit clear positive effects in any of the C. briggsae strains tested, but exhibited toxicity at high millimolar concentrations (c). None of the resveratrol doses assayed appeared to alter the median lifespan of any of the C. briggsae strains tested (d). PG showed a negative effect on median lifespan for all of the C. briggsae strains tested at low millimolar concentrations (e). Median lifespans were determined from single plate populations. Mean values are plotted here with small bars, indicating the s.e. (sample size and statistical summaries are included in Supplementary Data 5).