title: Dietary Linseed Oil Reduces Growth While Differentially Impacting LC-PUFA Synthesis and Accretion into Tissues in Eurasian Perch (Perca fluviatilis).
abstract: The aim of this study was to evaluate the impact of replacing dietary fish oil (FO) with linseed oil (LO) on growth, fatty acid composition and regulation of lipid metabolism in Eurasian perch (Perca fluviatilis) juveniles. Fish (17.5 g initial body weight) were fed isoproteic and isoenergetic diets containing 116 g/kg of lipid for 10 weeks. Fish fed the LO diet displayed lower growth rates and lower levels of DHA in the liver and muscle than fish fed the FO diet, while mortality was not affected by dietary treatment. However, DHA content recorded in the liver and muscle of fish fed the LO diet remained relatively high, despite a weight gain of 134 % and a reduced dietary level of long-chain polyunsaturated fatty acids (LC-PUFA), suggesting endogenous LC-PUFA biosynthesis. This was supported by the higher amounts of pathway intermediates, including 18:4n-3, 20:3n-3, 20:4n-3, 18:3n-6 and 20:3n-6, recorded in the liver of fish fed the LO diet in comparison with those fed the FO diet. However, fads2 and elovl5 gene expression and FADS2 enzyme activity were comparable between the two groups. Similarly, the expression of genes involved in eicosanoid synthesis was not modulated by dietary LO. Thus, the present study demonstrated that in fish fed LO for 10 weeks, growth was reduced but DHA levels in tissues were largely maintained compared to fish fed FO, suggesting a physiologically relevant rate of endogenous LC-PUFA biosynthesis capacity.
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur (UNamur), Rue de Bruxelles 61, 5000, Namur, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Geay
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur (UNamur), Rue de Bruxelles 61, 5000, Namur, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Wenon
authors.affiliation: Institut des Sciences de la Vie, UCLouvain, Croix du Sud, 2/L7.05.08, 1348, Louvain-La-Neuve, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Mellery
authors.affiliation: Unité de Chimie Physique Théorique et Structurale, Université de Namur (UNamur), Rue de Bruxelles 61, 5000, Namur, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Tinti
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur (UNamur), Rue de Bruxelles 61, 5000, Namur, Belgium.
authors.forename: S N M
authors.initials: SN
authors.lastname: Mandiki
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
authors.forename: D R
authors.initials: DR
authors.lastname: Tocher
authors.affiliation: Institut des Sciences de la Vie, UCLouvain, Croix du Sud, 2/L7.05.08, 1348, Louvain-La-Neuve, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Debier
authors.affiliation: Institut des Sciences de la Vie, UCLouvain, Croix du Sud, 2/L7.05.08, 1348, Louvain-La-Neuve, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Larondelle
authors.affiliation: Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur (UNamur), Rue de Bruxelles 61, 5000, Namur, Belgium. patrick.kestemont@unamur.be.
authors.forename: P
authors.initials: P
authors.lastname: Kestemont
mesh_terms: D000123:Acetyltransferases / Q000378:metabolism; D000818:Animals; D017756:Aquaculture; D004032:Diet / Q000662:veterinary*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D000081031:Fatty Acid Elongases; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism; D005395:Fish Oils / Q000378:metabolism; D029941:Fish Proteins / Q000378:metabolism; D005602:France; D018507:Gene Expression Regulation, Developmental; D008043:Linseed Oil / Q000008:administration & dosage* / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D018482:Muscle, Skeletal / Q000254:growth & development / Q000378:metabolism*; D010471:Perches / Q000254:growth & development / Q000378:metabolism*; D017747:Seafood / Q000032:analysis*; D016019:Survival Analysis; D015430:Weight Gain
chemical_list: D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005395:Fish Oils; D029941:Fish Proteins; D008043:Linseed Oil; D044943:Fatty Acid Desaturases; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases
keywords: Eicosanoid; Eurasian perch; FADS2; Fatty acid metabolism; LC-PUFA