RESUMEN
The regulation of adipocyte differentiation is an important factor for production efficiency and meat quality in the poultry industry. The purpose of this study was to develop a new in vitro model of adipogenic differentiation of chicken embryonic fibroblasts (CEF). In this study, CEF were isolated at embryonic day (E) 5, and adipogenic differentiation was induced with supplementation of fatty acids (FA) and/or insulin (Ins) for 48 h. Oil-Red-O staining showed that lipid accumulation in E5 CEF was greater when supplemented with a combination of FA and Ins (FI) than other treatment groups (p < 0.05). Genes involved in differentiation of preadipocytes, fatty acid transport, and triacylglycerol synthesis were upregulated in the FI group compared to all other treatment groups (p < 0.01). Under myogenic media, the E5 CEF formed myotubes and expressed myogenic markers, myosin heavy chain (MHC), and myogenin (MyoG), suggesting myogenic potential of E5 CEF. To determine the permissive age window for adipogenic differentiation of CEF, E5, E6, and E7 CEF were induced for adipogenesis with FI treatment in 1%, 5%, or 10% chicken serum (CS). Among all embryonic ages, E5 with 10% CS showed the most lipid accumulation and the least myotube formation with the lowest expression of MHC and MyoG. These data indicate both adipogenic and myogenic potentials of E5 CEF, providing a new in vitro model for a better understanding of the processes of adipogenic and myogenic differentiation in chickens.