RT info:eu-repo/semantics/article T1 Metabolic and molecular evidence for long-chain PUFA biosynthesis capacity in the grass carp Ctenopharyngodon idella A1 Pérez Pérez, José Antonio A1 Marrero, Manuel A1 Monroig, Óscar A1 Navarro, Juan Carlos A1 Ribes-Navarro, Alberto A1 Galindo, Ana A1 Rodríguez, Covadonga A2 Biología Animal y Edafología y Geología A2 Grupo de investigación NUTRAHLIPIDS (Fisiología de los Lípidos y sus Derivados en la Alimentación Animal y Humana) K1 DHA K1 EPA K1 Fatty acyl desaturases K1 Elongation of very long-chain fatty acid protein K1 Grass carp AB There is a growing interest to understand the capacity of farmed fish species to biosynthesise the physiologicallyimportant long-chain (≥C20) n-3 and n-6 polyunsaturated fatty acids (LC-PUFAs), eicosapentaenoic acid (EPA),docosahexaenoic acid (DHA) and arachidonic acid (ARA), from their C18 PUFA precursors available in the diet. Infish, the LC-PUFA biosynthesis pathways involve sequential desaturation and elongation reactions from α-linolenicacid (ALA) and linoleic acid (LA), catalysed by fatty acyl desaturases (Fads) and elongation of very longchainfatty acids (Elovl) proteins. Our current understanding of the grass carp (Ctenopharyngodon idella) LCPUFAbiosynthetic capacity is limited despite representing the most farmed finfish produced worldwide. Toaddress this knowledge gap, this study first aimed at characterising molecularly and functionally three genes(fads2, elovl5 and elovl2) with putative roles in LC-PUFA biosynthesis. Using an in vitro yeast-based system, wefound that grass carp Fads2 possesses Δ8 and Δ5 desaturase activities, with Δ6 ability to desaturase not only theC18 PUFA precursors (ALA and LA) but also 24:5n-3 to 24:6n-3, a key intermediate to obtain DHA through the“Sprecher pathway”. Additionally, the Elovl5 showed capacity to elongate C18 and C20 PUFA substrates, whereasElovl2 was more active over C20 and C22. Collectively, the molecular cloning and functional characterisation offads2, elovl5 and elovl2 demonstrated that the grass carp has all the enzymatic activities required to obtain ARA,EPA and DHA from LA and ALA. Importantly, the hepatocytes incubated with radiolabelled fatty acids confirmedthe yeast-based results and demonstrated that these enzymes are functionally active. YR 2022 FD 2022 LK http://riull.ull.es/xmlui/handle/915/35423 UL http://riull.ull.es/xmlui/handle/915/35423 LA en NO https://doi.org/10.1016/j.cbpa.2022.111232 DS Repositorio institucional de la Universidad de La Laguna RD 10-may-2024