A neurogenetic mechanism of experience-dependent suppression of aggression

Aggression is an ethologically important social behavior 1 but excessive aggression can be detrimental to animal fitness 2,3 . Social experiences among conspecific individuals reduce aggression in a wide range of animals 4 . However, the genetic and neural basis for the experience-dependent suppression of aggression remains largely unknown. Here we found that nervy ( nvy ), a Drosophila homolog of vertebrate myeloid translocation gene (MTG) 5 involved in transcriptional regulation 6–8 , suppresses aggression via its action in a specific subset of neurons. Loss-of-function mutation of the nvy gene resulted in hyper-aggressiveness only in socially experienced flies, whereas overexpression of nvy suppressed spontaneous aggression in socially naïve flies. The loss-of-function nvy mutant exhibited persistent aggression under various contexts in which wild-type flies transition to escape or courtship behaviors. Knockdown of nvy in octopaminergic/tyraminergic (OA/TA) neurons increased aggression, phenocopying the nvy mutation. We found that a subpopulation of OA/TA cells specifically labeled by nvy is required for the social-experience-dependent suppression of aggression. Moreover, cell-type-specific transcriptomics on nvy -expressing OA/TA neurons revealed aggression-controlling genes that are likely downstream of nvy . Our results are the first to describe the presence of a specific neuronal subpopulation in the central brain that actively suppresses aggression in a social-experience-dependent manner, illuminating the underlying genetic mechanism.