Presented in Epiconcept Cost Action’s workshop Epigenomic Toolbox: from Methods to Models.
07-09 May 2014, Las Palmas, Spain
Studies in mammals and humans show that dietary influences exerted at critical developmental stages early in life (neonatal nutrition, post-natal nutrition) may have long-term consequences on physiological functions in later life. Nutritional programming phenomenon is largely studied in mammalian models for the understanding of diseases such as the metabolic syndrome or diabetes. The functioning of certain metabolic pathways such as fatty acid metabolism in juvenile fish also depends on specific nutritional signals during the critical larval periods, demonstrating that the concept of metabolic programming also exists in fish. Modulation of key enzymes for fatty acid synthesis is possible by feed given to juveniles. The present study will examine the influences early nutritional programming either during embryonic phase or during metamorphosis. To affect nutrient intake during these two periods either broodstock or early weaning diets were modified and their effects studied on sea bream performance, lipid metabolism, gene expression and response after a feeding challenge. Specific genes such as those involved in essential fatty acids metabolism, were markedly affected by the nutritional programing at both developmental windows. For instance an up regulation of delta-6 desaturase gene expression was obtained when fish was conditioned with moderate levels of vegetable oils, whereas extreme conditioning conditions inhibited the expression. Despite it was potentially possible to condition fish during metamorphosis, the larvae were very sensitive during this period and high mortalities occurred during the treatment. When fishes were programmed through broodstock nutrition, a very high survival rate was obtained. Even extreme conditioning produced reliabe survival rates. After treatment with different conditioning during the embryonic period, all fish were fed standard fishmeal diet for three months and, afterwards, challenged with vegetable oils. A significant positive effect of the nutritional programming was observed in lipid metabolism response as well as a better utilization of the feeds. Grant support: European Commission, Directorate for Research & Innovation, Grant Agreement KBBE-2001-5-288925 (ARRAINA)