title: Differential distribution of lipids in epidermis, gastrodermis and hosted Symbiodinium in the sea anemone Anemonia viridis.
abstract: Cnidarian-dinoflagellate symbiosis mainly relies on nutrient recycling, thus providing both partners with a competitive advantage in nutrient-poor waters. Essential processes related to lipid metabolism can be influenced by various factors, including hyperthermal stress. This can affect the lipid content and distribution in both partners, while contributing to symbiosis disruption and bleaching. In order to gain further insight into the role and distribution of lipids in the cnidarian metabolism, we investigated the lipid composition of the sea anemone Anemonia viridis and its photosynthetic dinoflagellate endosymbionts (Symbiodinium). We compared the lipid content and fatty acid profiles of the host cellular layers, non-symbiotic epidermal and symbiont-containing gastrodermal cells, and those of Symbiodinium, in a mass spectrometry-based assessment. Lipids were more concentrated in Symbiodinium cells, and the lipid class distribution was dominated by polar lipids in all tissues. The fatty acid distribution between host cell layers and Symbiodinium cells suggested potential lipid transfers between the partners. The lipid composition and distribution was modified during short-term hyperthermal stress, mainly in Symbiodinium cells and gastrodermis. Exposure to elevated temperature rapidly caused a decrease in polar lipid C18 unsaturated fatty acids and a strong and rapid decrease in the abundance of polar lipid fatty acids relative to sterols. These lipid indicators could therefore be used as sensitive biomarkers to assess the physiology of symbiotic cnidarians, especially the effect of thermal stress at the onset of cnidarian bleaching. Overall, the findings of this study provide some insight on key lipids that may regulate maintenance of the symbiotic interaction.
authors.affiliation: Université Nice Sophia Antipolis, UMR7138, Equipe Symbiose Marine, F-06000 Nice, France; Sorbonne Universités, UPMC Université Paris 06, Institut de Biologie Paris-Seine, UMR7138, F-75005 Paris, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Johana
authors.initials: J
authors.lastname: Revel
authors.affiliation: Université Nice Sophia Antipolis, Institut de Chimie de Nice, UMR7272, F-06000 Nice, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Massi
authors.affiliation: Université Nice Sophia Antipolis, Institut de Chimie de Nice, UMR7272, F-06000 Nice, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mehiri
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, Laboratoire Océanologique de Villefranche sur Mer, UMR 7093, F-06320 Villefranche-sur-Mer, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Boutoute
authors.affiliation: Sorbonne Universités, UPMC Université Paris 06, Laboratoire Océanologique de Villefranche sur Mer, UMR 7093, F-06320 Villefranche-sur-Mer, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mayzaud
authors.affiliation: Université Nice Sophia Antipolis, Institut de Chimie de Nice, UMR7272, F-06000 Nice, France; Centre National de la Recherche Scientifique, F-75005 Paris, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Capron
authors.affiliation: Université Nice Sophia Antipolis, UMR7138, Equipe Symbiose Marine, F-06000 Nice, France; Sorbonne Universités, UPMC Université Paris 06, Institut de Biologie Paris-Seine, UMR7138, F-75005 Paris, France; Centre National de la Recherche Scientifique, F-75005 Paris, France. Electronic address: Cecile.Sabourault@unice.fr.
authors.forename: Cécile
authors.initials: C
authors.lastname: Sabourault
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D004141:Dinoflagellida / Q000502:physiology*; D004817:Epidermis / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D018869:Heat-Shock Response; D050356:Lipid Metabolism; D012615:Sea Anemones / Q000378:metabolism*; D013312:Stress, Physiological; D013559:Symbiosis
chemical_list: D005227:Fatty Acids
keywords: Anemonia; Cnidarian bleaching; Hyperthermal stress; Lipidomics; Symbiodinium; Symbiotic interaction