Figure 2. clk-1 worms are sensitive to acute exposure to oxidative stress but resistant to chronic exposure.

Sensitivity to oxidative stress was assessed during development and adulthood using two superoxide-generating compounds: paraquat (PQ) and juglone. Chronic assays of oxidative stress could only be performed with paraquat because the toxicity of juglone is decreased within 8 hours. During development, clk-1 L2 larvae have decreased survival compared to wild-type worms under conditions of oxidative stress: A. 200 mM paraquat or B. 180 μM juglone. Similarly, in acute assays of oxidative stress assay on day 1 of adulthood, clk-1 worms show decreased survival compared to wild-type worms after exposure to either C. 200 mM paraquat or D. different concentrations of juglone (180–300 μM), indicating increased sensitivity to oxidative stress. E. In a chronic oxidative stress assay where worms are exposed to 4 mM paraquat beginning on day 1 of adulthood after development on NGM plates, clk-1 worms survive significantly longer than wild-type worms. F. However, clk-1 worms remain sensitive to acute oxidative stress throughout adulthood when exposed to 180 μM juglone. Overall, this shows that clk-1 worms are sensitive to acute oxidative stress throughout development and adulthood but are resistant to chronic oxidative stress during adulthood. Error bars indicate SEM. * p<0.05, *** p<0.001.