THE ROLE OF DIETARY LIPID ON THE STRESS RESPONSE BY SENEGAL SOLE SOLEA SENEGALENSIS KAUP LARVAE

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Teleost fish larvae adapt to dietary arachidonic acid supply through modulation of the expression of lipid metabolism and stress response genes

Publication . Alves Martins, Dulce; Rocha, Filipa; Martinez-Rodriguez, Gonzalo; Bell, Gordon; Morais, Sofia; Castanheira, Maria Filipa; Bandarra, Narcisa; Coutinho, Joana; Yufera, Manuel; Conceicao, Luis

Dietary fatty acid supply can affect stress response in fish during early development. Although knowledge on the mechanisms involved in fatty acid regulation of stress tolerance is scarce, it has often been hypothesised that eicosanoid profiles can influence cortisol production. Genomic cortisol actions are mediated by cytosolic receptors which may respond to cellular fatty acid signalling. An experiment was designed to test the effects of feeding gilthead sea-bream larvae with four microdiets, containing graded arachidonic acid (ARA) levels (0.4, 0.8, 1.5 and 3.0 %), on the expression of genes involved in stress response (steroidogenic acute regulatory protein, glucocorticoid receptor and phosphoenolpyruvate carboxykinase), lipid and, particularly, eicosanoid metabolism (hormone-sensitive lipase, PPAR alpha, phospholipase A(2), cyclo-oxygenase-2 and 5-lipoxygenase), as determined by real-time quantitative PCR. Fish fatty acid phenotypes reflected dietary fatty acid profiles. Growth performance, survival after acute stress and similar whole-body basal cortisol levels suggested that sea-bream larvae could tolerate a wide range of dietary ARA levels. Transcription of all genes analysed was significantly reduced at dietary ARA levels above 0.4%. Nonetheless, despite practical suppression of phospholipase A(2) transcription, higher leukotriene B-4 levels were detected in larvae fed 3.0% ARA, whereas a similar trend was observed regarding PGE(2) production. The present study demonstrates that adaptation to a wide range of dietary ARA levels in gilthead sea-bream larvae involves the modulation of the expression of genes related to eicosanoid synthesis, lipid metabolism and stress response. The roles of ARA, other polyunsaturates and eicosanoids as signals in this process are discussed.

2012-09Journal article

Open Access

Nutrition, quality and performance in marine fish larvae

Publication . Conceição, L. E. C.; Alves-Martins, D.; Engrola, S.; Gavaia, Paulo J.; Richard, Nadège; Aragão, C.

O cultivo de larvas de peixes marinhos é caracterizado por altas mortalidades e por problemas de qualidade, nomeadamente malformações esqueléticas. A solução de parte destes problemas passa por uma melhor compreensão dos requisitos nutricionais. Este trabalho pretende fazer uma revisão de trabalhos recentes que demonstram como os aminoácidos, os ácidos gordos e a vitamina K, mas também o regime alimentar, podem influenciar a qualidade e a performance das larvas de peixes marinhos.

2011Conference object

Open Access