EGFR and FGFR pathways have distinct roles in Drosophila mushroom body development and ethanol-induced behavior.

Abstract

Epidermal Growth Factor Receptor (EGFR) signaling has a conserved role in ethanol-induced behavior in flies and mice, affecting ethanol-induced sedation in both species. However it is not known what other effects EGFR signaling may have on ethanol-induced behavior, or what roles other Receptor Tyrosine Kinase (RTK) pathways may play in ethanol induced behaviors. We examined the effects of both the EGFR and Fibroblast Growth Factor Receptor (FGFR) RTK signaling pathways on ethanol-induced enhancement of locomotion, a behavior distinct from sedation that may be associated with the rewarding effects of ethanol. We find that both EGFR and FGFR genes influence ethanol-induced locomotion, though their effects are opposite - EGFR signaling suppresses this behavior, while FGFR signaling promotes it. EGFR signaling affects development of the Drosophila mushroom bodies in conjunction with the JNK MAP kinase basket (bsk), and with the Ste20 kinase tao, and we hypothesize that the EGFR pathway affects ethanol-induced locomotion through its effects on neuronal development. We find, however, that FGFR signaling most likely affects ethanol-induced behavior through a different mechanism, possibly through acute action in adult neurons.