Serotonin and insulin signaling team up to control growth in Drosophila

Abstract

Neuroendocrine signaling pathways play a central role in modulating animal body size in response to environmental signals. Little is known, however, regarding how these neuroendocrine circuits are controlled. An important advance in this area is reported in this issue of Genes & Development by Kaplan and colleagues (pp. 1877-1893), who show that serotonergic neurons regulate the growth of peripheral tissues in Drosophila through the insulin/IGF pathway.

Figure 1.

A model for the regulation of body size by Drosophila NS3. NS3 acts through serotonergic neurons to regulate DILP release by the insulin producing cells. The reduced level of released DILPs in ns3 mutants leads to decreased peripheral insulin signaling through the insulin receptor (InR) and downstream effector Akt1, resulting in reduced overall growth. Close apposition of serotonergic neuron and IPC projections suggest that these cells communicate through synaptic or paracrine signaling to coordinate growth with serotonin-modulated behaviors and the environment.