Intra-organ growth coordination in Drosophila is mediated by systemic ecdysone signaling

Regulation of final organ size is a complex developmental process that involves the integration of systemic and organ-specific processes. Previously, we have shown that in developing Drosophila, perturbing the growth of one imaginal disc – the parts of a holometabolous larva that become the external adult organs – retards growth of other discs and delays development, resulting in tight inter-organ growth coordination and the generation of a correctly proportioned adult. Whether different parts of the same imaginal disc similarly coordinate their growth to generate a functioning adult organ is, however, unclear. In this study, we use the wing imaginal disc in Drosophila to study and identify mechanisms of intra-organ growth coordination. We generate larvae in which the two compartments of the wing imaginal disc have ostensibly different growth rates (wild-type or growth-perturbed). We find that there is tightly coordinated growth between the wild-type and growth-perturbed compartments, w...