An EGF-responsive neural circuit couples insulin secretion with nutrition in Drosophila

Eleonora Meschi (1) , Pierre Léopold (1, 2) , Rénald Delanoue (1)

1 IBV - Institut de Biologie Valrose
2 Génétique et Biologie du Développement

Developing organisms use fine-tuning mechanisms to adjust body growth to ever-changing nutritional conditions. In Drosophila, the secretory activity of insulin-producing cells (IPCs) is central to couple systemic growth with amino acids availability. Here, we identify a subpopulation of inhibitory neurons contacting the IPCs (IPC-connecting neurons or ICNs) that play a key role in this coupling. We show that ICNs respond to growth-blocking peptides (GBPs), a family of fat-body-derived signals produced upon availability of dietary amino acids. We demonstrate that GBPs are atypical ligands for the fly EGF receptor (EGFR). Upon activation of EGFR by adipose GBPs, ICN-mediated inhibition of IPC function is relieved, allowing insulin secretion. Our study reveals an unexpected role for EGF-like metabolic hormones and EGFR signaling as critical modulators of neural activity, coupling insulin secretion to the nutritional status.

Mots clés: growth; insulin; inter-organ communication; nutrition; GBPs; neuronal circuit; EGF

Domaines: Biologie du développement; Neurobiologie

Eleonora Meschi, Pierre Léopold, Rénald Delanoue. An EGF-responsive neural circuit couples insulin secretion with nutrition in Drosophila. Developmental Cell, 2019, 48 (1), pp.76-86.e5. ⟨10.1016/j.devcel.2018.11.029⟩. ⟨hal-02313567⟩