Fig. 2. Mild overexpression of Rheb with hs-GAL4 (hs>Rheb) sensitizes adult flies to oxidative stress. Like control (hsGAL4/w) flies, hs>Rheb flies are not sensitive to daily feeding of 5% sucrose/PBS for 6 hours. However, hs>Rheb flies are sensitive to 5% H₂O₂ (mean survival is 33% after 5 days; n=166, P=0.0028) (A) as well as to another oxidative agent, paraquat (mean survival is 9% after 2 days; n=160, P=0.0006) (B). This mortality was not due to a general sensitivity of hs>Rheb flies to toxic compounds because these flies were found to be as sensitive to 25 mg/ml G418 as control flies (P=0.1193, NS). The mean survival on 25 mg/ml G418 is 64% for hsGAL4/w flies and 56% for hs>Rheb flies after 2 days (C). Error bars represent the s.d. Statistical comparison (T-test): all P values are based on comparison of the overexpressor with control.