Figure 2.

Life stage differences in heat shock responsiveness. (A) Survival was compared by scoring percent (%) survival of N2 wild-type worms at each larval stage. Worm growth plates were removed from 37°C as indicated. Three or four plates/ time point were counted for each developmental stage. L1 and L2 survival was assessed 2 days post-HS (Since HS causes a developmental delay, allowing worms to fully recover increased our confidence that only worms that will ultimately survive to adulthood and produce offspring were counted). L3 and L4 survival was assessed 12 -14 hours post-HS. There are no significant differences from 1.0 to 2.5 hrs when L1 worms are exposed to 37°C. Differences in survival following heat shock are significant beginning at 1.5 hrs of exposure to 37°C (compare L1 to L3 and L4, P=0.008 & 0.014, respectively, one-way ANOVA w/ Bonferroni correction). (B) Differences in survival of adult N2, wild-type worms when comparing worms exposed to 1.5 hours at 37°C at Day 1, 2, 3, or 4 of adulthood [71, 95, 119, 143 hours post egg-lay, respectively). Two plates were prepared as described in (A) for each age tested. Survival of day 1 worms is significantly different from day 2 and day 4 worms (P=0.02 and 0.02, respectively). Comparing day 1 to day 3 worms (P=0.054), they are not significantly different, but this is likely due to the small sample size in this experiment. Note: 1.5 hours was chosen for this experiment to ensure no plate had 0% survival.