RT Journal Article T1 Influence of Dietary Lipids and Environmental Salinity on the n-3 Long-Chain Polyunsaturated Fatty Acids Biosynthesis Capacity of the Marine Teleost Solea senegalensis A1 Marrero, Manuel A1 Monroig, Óscar A1 Betancor, Mónica A1 Giráldez Díaz, Inmaculada AB Fish vary in their ability to biosynthesise long-chain polyunsaturated fatty acids (LC-PUFA)depending upon the complement and function of key enzymes commonly known as fatty acyldesaturases and elongases. It has been reported in Solea senegalensis the existence of a D4 desaturase,enabling the biosynthesis of docosahexaenoic acid (DHA) from eicosapentaenoic acid (EPA), whichcan be modulated by the diet. The present study aims to evaluate the combined effects of thepartial replacement of fish oil (FO) with vegetable oils and reduced environmental salinity in thefatty acid composition of relevant body compartments (muscle, hepatocytes and enterocytes), theenzymatic activity over -linolenic acid (ALA) to form n-3 LC-PUFA through the incubation ofisolated hepatocytes and enterocytes with [1-14C] 18:3 n-3, and the regulation of the S. senegalensisfads2 and elovl5 in the liver and intestine. The presence of radiolabelled products, including 18:4n-3,20:4n-3 and EPA, provided compelling evidence that a complete pathway enabling the biosynthesisof EPA from ALA, establishing S. senegalensis, has at least one Fads2 with D6 activity. Dietarycomposition prevailed over salinity in regulating the expression of fads2, while salinity did so overdietary composition for elovl5. FO replacement enhanced the proportion of DHA in S. senegalensismuscle and the combination with 20 ppt salinity increased the amount of n-3 LC-PUFA in hepatocytes. PB MDPI SN 1660-3397 YR 2021 FD 2021-04 LK http://hdl.handle.net/10272/19944 UL http://hdl.handle.net/10272/19944 LA eng NO Marrero, M., Monroig, Ó., Betancor, M. ... Giráldez Díaz, I. (2021). Influence of Dietary Lipids and Environmental Salinity on the n-3 Long-Chain Polyunsaturated Fatty Acids Biosynthesis Capacity of the Marine Teleost Solea senegalensis. Marine Drugs, 19(5), 254. DOI: https://doi.org/10.3390/md19050254 DS Repositorio Institucional de la Universidad de Huelva RD 30 may 2026