Development under predation risk increases serotonin-signaling, variability of turning behavior and survival in adult fruit flies Drosophila melanogaster

Abstract

The development of high-throughput behavioral assays, where numerous individual animals can be analyzed in various experimental conditions, has facilitated the study of animal personality. Previous research showed that isogenic Drosophila melanogaster flies exhibit striking individual non-heritable locomotor handedness. The variability of this trait, i.e., the predictability of left-right turn biases, varies across genotypes and under the influence of neural activity in specific circuits. This suggests that the brain can dynamically regulate the extent of animal personality. It has been recently shown that predators can induce changes in prey phenotypes via lethal or non-lethal effects affecting the serotonergic signaling system. In this study, we tested whether fruit flies grown with predators exhibit higher variability/lower predictability in their turning behavior and higher survival than those grown with no predators in their environment. We confirmed these predictions and found that both effects were blocked when flies were fed an inhibitor (αMW) of serotonin synthesis. The results of this study demonstrate a negative association between the unpredictability of turning behavior of fruit flies and the hunting success of their predators. We also show that the neurotransmitter serotonin controls predator-induced changes in the turning variability of fruit flies, regulating the dynamic control of behavioral predictability.

Don’t Leave the Past Behind: How Larval Experience Shapes Pupal Antipredator Response inAedes aegypti

“…Krama et al, 2023;Maloney & McLean, 1995). Prior experience can alert the prey of a potential threat, and cause it to change its behaviour even in the absence of any obvious threat in its environment, as we observed in our study.…”

“…Such movements can make a prey’s location more unpredictable and help evade attacks by a potential predator (Humphries & Driver, 1970; Richardson et al, 2018). Early life experience is essential for acquiring information about predators and enhancing any innate strategy of evading a predator during an encounter (Griffin et al, 2000; Krama et al, 2023; Maloney & McLean, 1995). Prior experience can alert the prey of a potential threat, and cause it to change its behaviour even in the absence of any obvious threat in its environment, as we observed in our study.…”

“…One recent study has looked at the behavioural carryover of predation risk in a holometabolous life cycle. Krama et al, 2023 showed that the D. melanogaster adults with larval experience of predation risk show a behaviour change and survive better in the presence of predators than naive adults. Studies on antipredator defence and the carryover effects of predation often neglect the pupal stage (Lindstedt et al, 2019), perhaps because of the developmental role of the pupal stage relative to the larval (feeding) and adult (reproductive) stages.…”

A diabetes-like biochemical and behavioural phenotype of Drosophila induced by predator stress

“…Our finding that supporting serotonin synthesis antagonizes the described metabolic effects suggests a central role for serotonin in such biochemical communication. Serotonin has multiple biological functions: regulating courtship behaviour [ 54 ], affecting spatial memory [ 55 ] and olfactory learning [ 56 ], influencing phototactic behaviour [ 49 , 57 ], and affecting turning behaviour [ 58 ]. Furthermore, it participates in several pathways that overlap with the roles of other neurotransmitters, such as dopamine and octopamine (norepinephrine homologue in Drosophila ).…”