Transgenerational transfer of dietary lipids and its consequences for offspring physiology in a marine teleost

Maternal provisioning of nutrients can play a key role in the growth, development and long-term fitness of offspring. In teleosts, the composition of maternally derived nutrients (in yolk and oil) depends partly on maternal diet. This dissertation investigates the process of maternal-offspring nutrient transfer and the transgenerational effects of maternal nutrition on offspring physiology in a marine teleost, red drum (Sciaenops ocellatus). Results of 21 diet-shift experiments, from which the fatty acid profiles of the diets and eggs were compared, showed that 15 fatty acids in eggs were correlated with their levels in the recent diet, and the rate of incorporation of fatty acids into eggs was proportional to the magnitude of the diet shift. Further assessment revealed that maternal diet affected egg triglyceride (TG) content but not other lipid classes. Parental dietary variations rapidly affected the fatty acid composition of all major lipid classes in eggs (TG, wax ester/steryl ester (WE/SE), and phosphatidylcholine (PC)), with greater effects on neutral lipids (TG, WE/SE) than on the polar lipid (PC). Rates at which embryos and larvae utilized 15 fatty acids varied with maternal diet and were proportional to their initial concentrations in eggs. Rates of utilization of the oil globule were also affected by maternal diet, resulting in differences in oil globule size at the first feeding stage. Effects of different maternal diets on larval fatty acid compositions persisted at the time of onset of exogenous feeding and afterward. In addition, prolonged effects of maternal nutrition on larval lipid metabolism (nutritional programming) were documented. At 21 days post-hatching (dph), larvae reared under common conditions from eggs produced by adults on different diets showed differences in total fatty acid accumulation and fatty acid profiles (especially polyunsaturated fatty acids in TG). Collectively, these research findings demonstrate some of the profound transgenerational effects of maternal nutrition on offspring physiology. The altered lipid metabolism of offspring resulting from variations in parental diet may have consequences for larval physiological processes and behavioral performance, which may ultimately influence their survival and fitness