Sex and Wolbachia endosymbiont modulate lipid profiles in terrestrial isopod Armadillidium vulgare

Most eukaryotic organisms live in close association with microorganisms known as symbionts, which influence host evolution, physiology, and ecosystem functioning. Among these, Wolbachia pipientis, a vertically transmitted endosymbiont widespread in arthropods, can manipulate host reproduction, such as feminizing genetic males in isopod crustaceans, raising the possibility that it also modulates host metabolism. Here, we investigated the impact of Wolbachia infection on the lipid composition of the woodlouse Armadillidium vulgare. Lipid profiling using TLC-FID, RP-LC-RI and GC-FID was performed on asymbiotic males, asymbiotic females, and Wolbachia-symbiotic females. Our results show that both sex and symbiont infection shape the quantitative distribution of lipid classes despite a largely conserved fatty acid spectrum. Males had higher proportions of polar (44.25%) and saturated (22.42%) lipids, whereas females accumulated more neutral lipids (46.39%), a trend amplified by Wolbachia carriage (53.58%). These shifts likely reflect targeted manipulation of host lipid metabolism by Wolbachia, altering hydrocarbon abundance, optimizing energy storage, and adjusting membrane composition to promote its persistence. Overall, our findings highlight the intersecting roles of sex and symbiont carriage in shaping the lipid landscape of woodlice and suggest that lipid remodeling is a key mechanism by which Wolbachia ensures its viability and reproductive success.