Meeting Abstract
Periods of social instability can elicit pronounced changes in behavior and adaptive re-allocation of resources to promote success in future competition. However, the molecular mechanisms underlying this phenotypic plasticity are unclear in the natural and dynamic social environments faced by free-living animals. Here, we experimentally generated intense social instability for a wild, cavity-nesting female songbird (tree swallows, Tachycineta bicolor). We reduced nest box availability after initial settlement, generating heightened competition; 24hr later, we returned boxes, causing aggressive interactions to subside. We collected females during the peak of competition and after it had ended, along with date-matched controls. We measured transcriptomic responses in two behaviorally relevant brain regions, the hypothalamus and ventromedial telencephalon. Gene set enrichment and network analyses suggest processes related to energy mobilization were upregulated during and after competition, while sensory perception and hormone processing were not upregulated until after competition had ended. Immune-related gene regulation was more complex, with lymphocyte processes downregulated during competition and antigen presentation upregulated after competition. Our data also hint at epigenetic mechanisms that may mediate the lasting effects of competition. By experimentally manipulating competition in the wild, these data collectively show how natural social instability causes shifts in gene expression that may facilitate the demands of competition at the expense of self-maintenance. Further, some of these effects persist after competition has ended, suggesting individuals may be “primed” for success in future social instability.
