Modulation of sensory perception by hydrogen peroxide enables Caenorhabditis elegans to find a niche that provides both food and protection from hydrogen peroxide
Fig 1
Hydrogen peroxide alters the bacterial food preference of C. elegans.
(A) Diagram summarizing experimental strategy (top) and series of pictures of the E. coli MG1655 and JI377 lawns at the specified timepoints from representative food-choice assays (bottom) without added H2O2 (left) and with 1 mM H2O2 (right). (B) The proportion of nematodes on the E. coli MG1655 and JI377 lawns in assays without added H2O2 (left) and with 1 mM H2O2 (right) is plotted against time. P < 0.001 for times other than zero (ANOVA). n ≥ 15 assays per condition. (C) The food-choice indices for the assays shown in (B) are plotted against time. H2O2 induced an increase in food-choice index. Groups labeled with different letters exhibited significant differences (P < 0.05, Tukey HSD test) otherwise (P > 0.05). (D) The H2O2-dependent increase in the proportion of nematodes on the E. coli MG1655 lawns compared to JI377 lawns in two-hour food-choice assays was absent in choice-trap assays, in which the paralytic agent sodium azide was added to the bacterial lawns. ** indicates P < 0.002 and “ns” indicates P > 0.05 (standard least-squares regression). (E) The H2O2-induced increase in food-choice index was absent in choice-trap assays, for the assays shown in (D). Groups labeled with different letters exhibited significant differences (P < 0.01, Tukey HSD test) otherwise (P > 0.05). Data are represented as mean ± s.e.m.
