Fig. 2: Thiol level in C. elegans depends on the diet.

a Killed bacteria have a lower level of reduced thiols. Live or dead (heat inactivated) E. coli OP50 spotted onto NGM plates. After three days, bacteria were scraped and the total amount of reduced thiols (left panel) and GSH (right panel) was determined. Error bars, mean ± SEM from three independent experiments. b The level of thiols in C. elegans depends on the thiols content in the diet. L4 stage animals were transferred to LB, DB or DB + NAC plates, incubated for three days, and the total amount of reduced thiols (left panel, n~800) and GSH (right panel, n~2600) was determined. Error bars, mean ± SEM from at least 8 independent experiments. See also Supplementary Table 3. c Thiols supplemented in the medium or acquired from live bacteria promote oxidative stress resistance. N2 (wt) animals were grown on live bacteria (LB), dead bacteria (DB), or DB + NAC plates. At day 2 of adulthood they were transferred to plates spotted with DB and supplemented with 150 mM paraquat. Error bars, mean ± SEM from three independent experiments (n = 120). d, e Representative image and quantification of thiols staining in live C. elegans. L4 stage animals were transferred to LB or DB plates supplemented with chemicals as indicated, incubated for three days, picked, washed, and stained with ThioFluor 623 to detect intracellular reduced thiols. Box plots indicate median (middle line), 25th, 75th percentile (box) and 5th and 95th percentile (whiskers) as well as maximum, minimum and mean (single points). n = 94–128 worms over three independent experiments. See also Supplementary Table 4. In all graphs p values are: n.s. not significant; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; two-tailed t-tests.