The contributions of hepatic de novo lipogenesis to the difference in body fat mass of genetically lean and fat duck breeds

Abstract

The underlying reasons for genetic differences in body fat mass remain unclear. The objective of this study was to investigate the contributions of hepatic de novo lipogenesis (DNL) to the genetic differences in fat mass in ducks. Ducks with distinct genetic backgrounds were selected for the genetically lean and fat animal models. The weights of fat tissue and organs as well as the gene expressions, enzyme activities and concentrations related to hepatic lipogenesis were measured and compared between the two genetically different duck breeds. Although a clear phenotypic difference in extra-liver fat mass between the two genetically different duck breeds was observed, the relative weights of the fat tissue to body weight in the two breeds were similar. There were no clear divergences regarding DNL-related gene expressions (Acc, Dgat2 and Fas), enzyme activities (ELVOL and FAS) and enzyme concentrations (ACC) between the two genetically different duck breeds, suggesting that hepatic DNL may contribute less to the individual fat mass difference in ducks; rather, body fat mass may depend more on the liver size. Our findings may provide a fundamental explanation for individual fat mass differences.