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

Predation can have both lethal and non-lethal effects on prey. The non-lethal effects of predation can instil changes in prey life history, behaviour, morphology and physiology, causing adaptive evolution. The chronic stress caused by sustained predation on prey is comparable to chronic stress conditions in humans. Conditions like anxiety, depression, and post-traumatic stress syndrome have also been implicated in the development of metabolic disorders such as obesity and diabetes. In this study, we found that predator stress induced during larval development in fruit flies Drosophila melanogaster impairs carbohydrate metabolism by systemic inhibition of Akt protein kinase, which is a central regulator of glucose uptake. However, Drosophila grown with predators survived better under direct spider predation in the adult phase. Administration of metformin and 5-hydroxytryptophan (5-HTP), a precursor of the neurotransmitter serotonin, reversed these effects. Our results demonstrate a direct link between predator stress and metabolic impairment, suggesting that a diabetes-like biochemical phenotype may be adaptive in terms of survival and reproductive success. We provide a novel animal model to explore the mechanisms responsible for the onset of these metabolic disorders, which are highly prevalent in human populations.

Automated summary

Predation can have lethal and non-lethal effects on prey, and non-lethal effects can cause adaptive evolution. Chronic predation stress can lead to metabolic disorders, similar to conditions in humans. This study found that predator stress impairs carbohydrate metabolism in fruit flies, but the flies grown with predators have better survival under direct predation. Treatment with metformin and 5-hydroxytryptophan reversed these effects, suggesting a link between predator stress and metabolic impairment. This research provides an animal model to explore the mechanisms behind prevalent metabolic disorders in humans.