Neuroendocrine control of catch-up growth in Drosophila

Children and other vertebrate animals stunted due to malnutrition can compensate for this deficit by resuming growth at a higher-than-normal rate via a still ill-defined mechanism. High mortality and adverse effects later in life may offset the positive effects of catch-up growth. Here we report that the invertebrate Drosophila melanogaster also experiences catch-up growth following a period of starvation, and the relaxin receptor Lgr4 instigates this catch-up growth. Starved larvae compensate for weight loss by growing two or more times faster and starting maturation within the same time as the non-starved sibling by preventing a rise in insulin-like growth (IGF)-induced ecdysone under Lgr4 control. Our data reveal that catch-up growth is associated with a surge of insulin, not IGF, which may clarify how catch-up growth often leads to metabolic problems and obesity.