The effect of ration size on the muscle fatty acid profile and gene expression of key enzymes involved on tissue fatty acid uptake, polyunsaturated fatty acid (PUFA) biosynthesis and phospholipid (PL) metabolism was addressed in juvenile gilthead sea bream. Feed restriction was accompanied by a reduced muscle lipid deposition and triglyceride (TG)/PL ratio. The fatty acid profile of TG was not altered by ration size, whereas the PL fraction was enriched on long-chain PUFA, especially docosahexaenoic acid (DHA) and arachidonic acid (ARA). These changes on fatty profile were associated to the up-regulated mRNA expression of the lipoprotein lipase-like, which may favour the selective tissue fatty acid uptake of LC-PUFA from circulating lipoproteins. In parallel, lipogenic markers such as ¿9 desaturase enzymes were markedly down-regulated with the reduction of feed intake. These findings highlight the allostatic regulation of PL as a conserved mechanism throughout vertebrate evolution, which is probably involved to the increase of insulin sensitivity with feed restriction.

Ponencia presentada en el XIII Congreso Nacional de Acuicultura celebrado en Barcelona del 21 al 24 de noviembre de 2011

Esta investigación ha sido financiada por los proyectos AQUAFAT (AGL2009-07797) y PROMETEO 2010/06.

Peer Reviewed