Fig. 1. Larval growth pattern and experimental outline. (A) Drosophila larvae pupariate 5 days AEL under standard conditions, i.e. 25°C, non-crowding. They undergo two molts and grow rapidly in size. The 70 h point is not a morphologically or behaviourally identifiable stage, in contrast to pupariation, wandering behaviour or feeding stoppage (see text for details). (B) Larvae grown on yeast paste on apple juice agar plates (47–49 h AEL) were washed and transferred to appropriate nutrient conditions. After 1, 4 and 12 h, total RNA was isolated and hybridized to microarrays. (C) Three categories were formed based on the expression profile of genes after 4 h treatment in starvation (st 4h) and sugar (su 4h) conditions (see text for details).