Essential Fatty Acid Assimilation and Synthesis in Larvae of the Bivalve Crassostrea gigas
|Author(s)||Da Costa Gonzalez Fiz1, 2, Robert Rene1, 3, Quere Claudie1, Wikfors Gary H.4, Soudant Philippe5|
|Affiliation(s)||1 : Ifremer/Laboratoire des sciences de l’Environnement Marin (UMR 6539, LEMAR), 29280, Plouzané, France
2 : Novostrea Bretagne, Route du Vieux Passage, Banastère, 56370, Sarzeau, France
3 : IFREMER, Unite Littoral, Ctr Bretagne, F-29280 Plouzane, France.
4 : NOAA, Northeast Fisheries Sci Ctr, NMFS, Milford, CT 06460 USA.
5 : IUEM UBO, LEMAR, Lab Sci Environm Marin UMR 6539, Plouzane, France.
|Source||Lipids (0024-4201) (Springer Heidelberg), 2015-05 , Vol. 50 , N. 5 , P. 503-511|
|WOS© Times Cited||32|
|Keyword(s)||Fatty acid, Larvae, Lipids, Metabolism, Oyster, Synthesis|
|Abstract||Essential fatty acids (EFA) are important for bivalve larval survival and growth. The purpose of this study was to quantitatively assess for the first time through a mass-balance approach dietary EFA incorporation and synthesis within Crassostrea gigas larvae. A first experiment was carried out using two microalgae, Tisochrysis lutea (T) and Chaetoceros neogracile (Cg), as mono- and bi-specific diets. A second experiment using a similar design was performed to confirm and extend the results obtained in the first. Flow-through larval rearing was used for accurate control of food supply and measurement of ingestion. Non-methylene-interrupted fatty acids were synthetized from precursors supplied in the diet: 16:1n-7 and 18:1n-9, mediated by Delta 5 desaturase. Moreover, this Delta 5 desaturase presumably allowed larvae to convert 20:3n-6 and 20:4n-3 to 20:4n-6 and 20:5n-3, respectively, when the product EFA were poorly or not supplied in the diet, as when larvae were fed T exclusively. Under our experimental conditions, none of the diets induced 22:6n-3 synthesis; however, 22:6n-3 incorporation into larval tissues occurred selectively under non-limiting dietary supply to maintain optimal levels in the larvae. This combination of flow-through larval rearing and biochemical analysis of FA levels could be applied to additional dietary experiments to precisely define optimal levels of EFA supply.|