Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster

Abstract

In many animal species, learning and memory have been found to play important roles in regulating intra-and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short-and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.loser/winner effects | aggression | learning and memory | behavior | Drosophila melanogaster

Life history of aggression: effects of age and sexual experience on male aggression towards males and females

“…It is thus likely that the major cost of maleemale and maleefemale aggression in fruit flies is increased mortality rates associated with heightened activity. Another possible cost is the increased tendency to lose a fight after a previous loss (Hsu, Earley, & Wolf, 2006;Trannoy, Penn, Lucey, Popovic, & Kravitz, 2016). Such loser effects may vary in magnitude with age and experience (Fawcett & Johnstone, 2010).…”

Genetic variation in social environment construction influences the development of aggressive behavior in Drosophila melanogaster

“…This 'spaced training' type of experience is similar to the experience recorded in the morning and evening of day 1 in the Development experiment and may occur in nature as well, as males are moderately site faithful and may encounter the same male repeatedly (Stamps et al, 2005). Understanding how experiences with males and females contribute to male behavioral development (Yurkovic et al, 2006;Wang et al, 2008;Yuan et al, 2014;Trannoy et al, 2016) and how females contribute to the dynamics of male-male aggression (Foley et al, 2015) would provide a fuller picture of how social interactions unfold among interacting individuals and over time in ecologically relevant social environments.…”

“…Recently, Trannoy et al (2016) showed in laboratory genotypes that the duration of loser effects depends on the duration of social experience: loser effects only last beyond 24 h if initial exposure to attacks from stimulus males occur repeatedly over time (Trannoy et al, 2016). This 'spaced training' type of experience is similar to the experience recorded in the morning and evening of day 1 in the Development experiment and may occur in nature as well, as males are moderately site faithful and may encounter the same male repeatedly (Stamps et al, 2005).…”

Social status and modern‐type depression: A review

“…Therefore, winners find it easier to win the next competition, while losers will continue to lose (Hsu et al, ). This phenomenon is called the “winner/loser effect,” which has a strong influence on the regulation of social status in many species (Hsu & Wolf, ; Trannoy, Penn, Lucey, Popovic, & Kravitz, ; Zilioli & Watson, ). Since survival resources (e.g., food, reproductive females) are limited in nature, social hierarchy enables the appropriate distribution of these resources and the continued existence of the species (Halevy et al, ).…”