Hippo signaling instructs ectopic but not normal organ growth [Drosophila NonPupatingLarvae]

We fed wildtype larvae a special diet that lacks precursor molecules necessary for the synthesis of the molting hormone ecdysone required for pupation, thus keeping animals in the larval stage. Importantly, in these larvae, the imaginal discs grow until their terminal size is reached but they do not proceed with differentiation as this requires a pulse of ecdysone. This method thus allowed us to directly compare actively growing discs with discs at the same developmental stage that terminated proliferation after reaching their proper size. Differential gene expression analysis of samples of eye-antennal imaginal discs from larvae raised on pupation-preventing food at two time points: 5 days after egg laying - before pupation would normally begin and eye discs are still actively growing ("actively growing"); 11 days after egg laying - after pupation would normally have begun and eye discs terminated proliferation after reaching their proper size ("growth completed").