Figure 6.

Distinct Effects on Energy Homeostasis Resulting from Pan-Tracheal or Gut-Specific Reductions in Tracheal Terminal Branching

(A) Reduced growth of most tracheal terminal cells (achieved using DSRF>btl-RNAi) does not affect the time between egg laying and pupation (only the two controls are significantly different from one another, p < 0.001, n = 40 larvae/set).

(B) This genetic manipulation leads to shorter-lived adult male flies in the presence of nutritious food (p < 0.0001 for all three comparisons, n = 70–120 flies/set).

(C) DSRF>btl-RNAi larvae have an increased length to width ratio (p < 0.001 versus GAL4 control, p < 0.0001 versus UAS control, n = 30 samples/set, total 300 larvae/set).

(D) They also have a reduced fat/protein content ratio (p < 0.0001 versus GAL4 control and p = 0.013 versus UAS control, n = 19 samples/set, total 190 larvae/set).

(E) An increase in free glycerol is also apparent in their hemolymph (p = 0.002 versus GAL4 control, p < 0.001 versus UAS control, n = 13 samples/set, total 130 larvae/set).

(F) A gut-specific reduction in tracheal terminal cell growth (achieved using DSRF>InR-RNAi) does not affect the survival of adult male flies in well-fed conditions (n = 60–140 flies/set).

(G) The same genetic manipulation leads to enhanced survival when adult male flies are subject to nutrient restriction (p < 0.0001 versus either control, p < 0.001 GAL4 versus UAS controls, n = 110–120 flies/set).

(H and I) The lipid stores of these adult males are relatively normal in well-fed conditions (H, p = 0.001 versus UAS control but not significant versus GAL4 control, p = 0.002 GAL4 versus UAS controls, n = 7 samples/set, total 70 flies/set), but they are more reduced than those of controls upon nutrient restriction (I, p = 0.002 versus either UAS or GAL4 controls, n = 7 samples/set, total 70 flies/set). See also Figure S7.