Ontogeny of hepatic metabolism in mule ducks highlights different gene expression profiles between carbohydrate and lipid metabolic pathways

International audience ; Background: The production of foie gras involves different metabolic pathways in the liver of overfed ducks suchas lipid synthesis and carbohydrates catabolism, but the establishment of these pathways has not yet beendescribed with precision during embryogenesis. The early environment can have short- and long-term impacts onthe physiology of many animal species and can be used to influence physiological responses that is calledprogramming. This study proposes to describe the basal hepatic metabolism at the level of mRNA in mule duckembryos in order to reveal potential interesting programming windows in the context of foie gras production. To this end, a kinetic study was designed to determine the level of expression of selected genes involved in steatosis-related liver functions throughout embryogenesis.The livers of 20 mule duck embryos were collected every 4 days from the 12th day of embryogenesis (E12) until 4days after hatching (D4), and gene expression analysis was performed. The expression levels of 50 mRNAs werequantified for these 7 sampling points and classified into 4 major cellular pathways.Results: Interestingly, most mRNAs involved in lipid metabolism are overexpressed after hatching (FASN, SCD1,ACOX1), whereas genes implicated in carbohydrate metabolism (HK1, GAPDH, GLUT1) and development (HGF, IGF,FGFR2) are predominantly overexpressed from E12 to E20. Finally, regarding cellular stress, gene expression appears quite stable throughout development, contrasting with strong expression after hatching (CYP2E1, HSBP1, HSP90AA1).Conclusion: For the first time we described the kinetics of hepatic ontogenesis at mRNA level in mule ducks and highlighted different expression patterns depending on the cellular pathway. These results could be particularly usefulin the design of embryonic programming for the production of foie gras.