atic metabolism genes typically show only low fold changes, even when compar ing highly contrasting nutritional compositions, compared to immune response genes that tend to be regulated with higher magnitudes of change. Hence, nutritional data such as the present data have been ana lysed these previously without multiple testing correction and this was found to result in relevant biological interpreta tions, when validated by reverse transcription real time quantitative PCR. For this reason, we examined the significant effects of n 3 LC PUFA without the correction, and from within the list contain ing 1951 features, we identified and categorized all 48 lipid metabolism transcripts present. An effect on cholesterol metabolism was apparent for the factor n 3 LC PUFA, with several genes of the biosynthesis path way and its regulation being down regulated in fish with a high n 3 LC PUFA phenotype.

In addition, glyceropho spholipid synthesis, lipid hydrolysis and eicosanoid syn thesis and metabolism were also affected, while other genes were associated with lipid and fatty acid transport, fatty acid synthesis and regulation of lipid metabolism. Validation of results by RT qPCR To validate the microarray analysis results, expression of selected genes was quantified by RT qPCR. These genes were chosen from lipid metabolism pathways that were more highly affected by the factor n 3 LC PUFA, and also included immune response genes, which was the category most highly affected by both n 3 LC PUFA and total lipid factors.

In addition, the expression of two fatty acyl desaturases and one elongase, which are typically responsive to diet ary levels of n 3 LC PUFA were also determined. The LC PUFA biosynthesis pathway was not identified by the microarray analysis as being differentially expressed in families Carfilzomib with different n 3 LC PUFA flesh contents but, given the potential importance of this pathway in determining n 3 PUFA phenotypes, we specifically aimed to verify this result. The RT qPCR results con firmed that genes involved in LC PUFA biosynthesis were not differentially expressed in families with higher and lower levels of n 3 LC PUFA.

Further more, the RT qPCR results confirmed significant down regulation of genes involved in hepatic cholesterol biosynthesis, such as isopentenyl diphosphate isomerase, inhibitor KPT-330 7 dehydrocholesterol reductase and sterol regulatory element binding protein 2 in families containing higher levels of n 3 LC PUFA in their flesh although this was only observed when this phenotype was also associated with low lipid level, except for 7dchr, which was significantly down regulated irrespect ive of lipid level. With regards to lipoprotein metabolism genes, general trends such as the magni tude and direction of change were broadly similar between the microarray and the RT qPCR analysis for the high ver sus low n 3 LC PUFA comparison at low lipid contents, although RT qPCR results were not significant. In the case of high lipid contents, the match betw