Figure 6.

Using MitoB to Assess the Role of Mitochondrial ROS In Vivo in Drosophila

(A) Typical life span curves for wild-type Drosophila under standard conditions (n = 200 per sex).

(B) Effect of age on the MitoP/MitoB ratio in wild-type flies. Flies injected with MitoB were incubated for 6 hr (females) or 3 hr (males), then extracted and analyzed by LC-MS/MS. Data are means ± SEM of three to five samples. Note that due to the different incubation times in these experiments (done for technical reasons, because males are smaller and therefore injected with proportionately less MitoB), the ratio values should not be compared directly between the sexes.

(C) DR affects fecundity and life span in female Drosophila. Data for wild-type Dahomey flies were adapted from (Grandison et al., 2009). DR was achieved by diluting the concentration of yeast provided in the food, at 0.5-, 1.0-, and 2.0-fold the standard amount. The fecundity index is a measure of cumulative egg-laying per female throughout life, which decreases under DR conditions, whereas median life span increases.

(D) Effect of DR on the MitoP/MitoB ratio in wild-type female flies. Flies were maintained on the indicated diets from 2 days. Flies were injected with MitoB, incubated for 6 hr, then extracted and analyzed by LC-MS/MS. Data are means ± SEM of four to five samples.

(E) Effect of activity on the MitoP/MitoB ratio in wild-type female Drosophila. Flies were maintained under standard “active” conditions, which allows flying and jumping, or under “inactive” conditions from day 2, where movement is spatially restricted and only walking is possible. Flies injected with MitoB were incubated for 3 hr, then extracted and analyzed by LC-MS/MS. Data are means ± SEM of four to five samples.

Statistical significance was determined by a two-tailed Student's t test: n/s p > 0.05, ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001.