The recent technologies that have led to the new field of functional genomics (how the genome of an organism regulates homeostasis and responds to stimuli) are providing a clearer understanding of how organisms interact with their environment and in particular their diet. We are beginning to learn how the diet may have long-term influence on performance and health. A form of epigenetic regulation has been recently described called fetal "programming". Fueled by epidemiological data the "fetal origins" hypothesis suggests that a poor in utero environment resulting from maternal dietary or placental insufficiency may "program" susceptibility in the fetus to cardiovascular or metabolic disorders. We have observed similar apparent programming by dietary manipulation in the chicken. When birds are challenged with a diet low in phosphorus (P) for 90 hours post-hatch they obtain the ability to better utilize P later in life. This increased retention of P from the diet can partially be explained by an enduring increase in the expression of the intestine-specific Na/P cotransporter (NaPcoT) gene during programming as well as later in life when fed P restricted diets. The resulting data provide the first evidence for neonatal programming of gene expression in an oviparous species.
epigenetics; functional genoimcs; nutrition; nutritional conditioning; poultry
