title: Insulin signalling mediates the response to male-induced harm in female Drosophila melanogaster.
abstract: Genetic manipulations in nutrient-sensing pathways are known to both extend lifespan and modify responses to environmental stressors (e.g., starvation, oxidative and thermal stresses), suggesting that similar mechanisms regulate lifespan and stress resistance. However, despite being a key factor reducing female lifespan and affecting female fitness, male-induced harm has rarely been considered as a stressor mediated by nutrient sensing pathways. We explored whether a lifespan-extending manipulation also modifies female resistance to male-induced harm. To do so, we used long-lived female Drosophila melanogaster that had their insulin signalling pathway downregulated by genetically ablating the median neurosecretory cells (mNSC). We varied the level of exposure to males for control and ablated females and tested for interacting effects on female lifespan and fitness. As expected, we found that lifespan significantly declined with exposure to males. However, mNSC-ablated females maintained significantly increased lifespan across all male exposure treatments. Furthermore, lifespan extension and relative fitness of mNSC-ablated females were maximized under intermediate exposure to males, and minimized under low and high exposure to males. Overall, our results suggest that wild-type levels of insulin signalling reduce female susceptibility to male-induced harm under intense sexual conflict, and may also protect females when mating opportunities are sub-optimally low.
authors.affiliation: Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK.
authors.forename: Irem
authors.initials: I
authors.lastname: Sepil
authors.affiliation: Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK.|Instituto Cavanilles of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain.
authors.forename: Pau
authors.initials: P
authors.lastname: Carazo
authors.affiliation: Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK.|Jesus College, University of Oxford, Turl Street, Oxford OX1 3DW, UK.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Perry
authors.affiliation: Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK.
authors.forename: Stuart
authors.initials: S
authors.lastname: Wigby
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005838:Genotype; D007328:Insulin / Q000378:metabolism*; D008017:Life Expectancy; D008297:Male; D012726:Sexual Behavior, Animal; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D007328:Insulin