Changes in liver metabolic pathways induced by dietary energy and selection for muscle fat content in rainbow trout

摘要

Levels of fat storage and allocation within fish body compartments strongly affect product quality (Johansson et al. 2000; Morkore et al., 2001). On the contrary to other farmed animals, there is no agreement on the ideal muscle fat content in fish, since a moderate level is preferred for fresh products and a higher level for smoked fillet. Genetic selection and dietary treatment are currently the main tools to manage muscle fat content, but their respective effects on metabolic pathways responsiblefor muscle fattening is still poorly understood. Fattening results from the balance between the supply by both dietary fat and de novo synthesis of fatty acid from carbohydrates, and fatty acid oxidation for energy production. In fish, lipogenesis mainly occurs in the liver, the centre of intermediary metabolism. The objective of the present study was to identify hepatic metabolic pathways that contribute to muscle fat deposition under both genetic selection and dietary manipulation.