Research advances of adipocyte differentiation in poultry

Preadipocytes are distinct precursor cells with the ability to generate and differentiate into adipocytes - a process that is regulated by a variety of genes. Adipocyte differentiation has been extensively studied in mammals; however, little is known about adipocyte differentiation in poultry. This review summarises the isolation, in vitro culture and characterisation of poultry preadipocytes. The most commonly used method for isolating primary preadipocytes is collagenase digestion and the cells are cultured in an incubator with 5% CO2 at 37°C. Preadipocytes of most species can differentiate into mature adipocytes using a combination of growth factors (a so-called 'hormone cocktail'), which include 3-isobutyl-1-methylxanthine (IBMX), dexamethasone (DEX) and insulin. Only the addition of a fatty acid mixture, transferrin, insulin and albumin induced primary preadipocyte differentiation, indicating that exogenous fatty acids are key factors that influence this process in chickens. As for the molecular regulation of poultry preadipocytes, studies have found several transcription factors that regulate adipose differentiation, which included peroxisome proliferator-activated receptors (PPARs), CCAAT/enhancer binding proteins (C/EBPs) and sterol response element-binding proteins (SREBPs). These transcription factors have been shown to regulate adipocyte differentiation by affecting the expression levels or activity of target genes.