Modulation of energy metabolism and epigenetic landscape in rainbow trout fry by a parental low protein/high carbohydrate diet

In rainbow trout (Oncorhynchus mykiss), the effect of a paternal and a maternal high carbohydrate/low protein diet was assessed on progeny. To this purpose, two-year old males and females rainbow trout were fed either a control diet or a high carbohydrate/low protein diet for an entire reproductive cycle for females and for 5 months for males. Crossed-fertilizations were carried out in order to obtain 4 groups of offspring. Before the first feeding, whole fry transcriptomes were compared to detect any impact of the parental diet on offspring metabolism. Two-year old male and female rainbow trout were fed either a control diet (NC, 63.89% protein and 0% carbohydrates) or a high carbohydrate/low protein diet (HC/LP, 42.96% protein and 35.30% carbohydrates) for an entire reproductive cycle for females and for 5 months for males. During the spawning period, spawns from NC and HC/LP females were cross-fertilized with milts from males from each experimental condition. Thus, offspring from 4 different conditions were obtained: NN (offspring from both males and females fed the control NC diet); HN (offspring from only females fed the HC/LP diet and males fed the control NC diet); NH (offspring from only males fed the HC/LP diet and females fed the NC diet); and HH (offspring from both parents fed the HC/LP diet). Whole fry were sampled before the first feeding.