composition of the diet in fish fed diets containing vegetable oil,
using a fish oil finishing diet before slaughter can restore the
EPA and DHA levels in fish flesh (Bell et al., 2003, 2004;
Torstensen et al., 2005).
Changes in dietary protein or fat source can have variable
metabolic consequences. To thoroughly evaluate such effects on
intermediary metabolism, an integrative approach is needed.
Data on growth performance, biochemical criteria, enzyme
activities and gene expression of rainbow trout fed with or
without fish oils (HL or LL fish) over 7 weeks have already
been reported (Ducasse-Cabanot et al., 2007). While unequivocal
characteristics have been detected for each dietary group
at the intestinal and plasma levels, no major changes were
detected in the liver. The analysis by a transcriptomic approach
should be able to answer the following question: is there really
‘weak or absence of liver response to dietary fish oil removal or
is it due to the restrictive candidate gene approach?. Here, we
undertake an analysis of the effects of diets with or without
added fish oil to have an overview of the effect per se of this
highly used ingredient on hepatic transcriptome using homologuous
rainbow trout cDNA microarray tools.