Fig 8.
Effect of reduced Relish and FOXO activity on gene expression, lipid storage, and survival in atf3 mutants. (A) Venn diagram showing the numbers of genes whose expression was normalized either by supplementing the atf3[A] transgene or by reducing the foxo or rel gene dose in atf376 mutants compared to the atf376 background. Gene names are shown in color according to functional categories shown in Fig. 3A. rel*, downregulation of relish was established by qRT-PCR on independent samples (see Fig. S5A in the supplemental material). (B) Decrease of lip3, CG5550, CG32302, and dro2 mRNAs toward control levels upon lowering rel and foxo dosages in atf376 larvae was validated by qRT-PCR on 4 to 6 independent RNA samples. (C) Amounts of TAG and DAG in third-instar atf376 larvae were reduced by rel or foxo heterozygosity, whereas the FFA titer was significantly lowered by removing one copy of rel, but not foxo. Lipids were assessed using thin-layer chromatography. (D) The total TAG content of third-instar larvae was lower in relE20 homozygotes than in w1118 controls. In contrast, overexpression of an active form of Relish (Rel-68) in the fat body and midgut using FB- or C7-Gal4 increased TAG levels. The TAG content was estimated using the TAG colorimetric assay. (E) atf376/Y relE20/+ animals survived better than their atf376/Y TM6B/+ siblings. All data in panels B to E are means and SEM; n ≥ 4; *, P < 0.05; **, P < 0.01; and ***, P < 0.001.