Fig. 2.

The central clock is susceptible to oxidative stress in foxo mutants. Flies were entrained to three light:dark cycles and transferred into DD with or without 1 mM PQ. On the fourth day of DD, brains were dissected at the indicated circadian times (CT) and immunostained with PER (red) and PDF (not shown) antibodies. At least six samples were examined for each time point, and representative confocal images of small ventral lateral neurons are shown. (A) In the absence of PQ, PER cycles normally in foxo mutants and y w controls. (B) In the presence of PQ, PER expression is reduced in foxo mutants. (C) Relative intensity of PER was blind-scored (mean ± SD). (Left) Control samples. (Right) PQ samples.