Fig. 4.

Ectopic insulin signaling in InsP₃R mutants increases TAG utilization upon starvation. (A) Starvation profile of itpr^ku with overexpression of either a dilp2⁺ transgene in the IPCs or overexpression of a PI3K^DA isoform in adult fat body and appropriate controls, as described below. (B) TAG levels in the abdomen of itpr^ku adult females overexpressing dilp2⁺ in the IPCs, under fed (F) and starved (S) conditions. The control was Dilp2GAL4/UASdilp2⁺; itpr^ug3/+ (C) TAG levels in the abdomen of itpr^ku adult females overexpressing PI3K^DA in adult fat body (FB), under fed (F) and starved (S) conditions. The control strain was UASPI3K^DA/2XGal80^ts; c729GAL4,itpr^ug3/+, which drives PI3K^DA expression in adult fat body at the restrictive temperature of 29°C (for B and C, *P<0.005, compared with controls at the same time-points). (D) Bodyweights of itpr^ku expressing dilp2⁺ and PI3K^DA are rescued partially (*P<0.005 compared with itpr^ku at the corresponding time in Fig. 1E; Student’s t-test). Conditions as described for Fig. 1E.