Peroxisome proliferator-activated receptor gamma (PPARγ), a key regulatory gene of lipid metabolism in chicken

The relationships between metabolic pathways, nutrients and genes are the basis of the majority of current studies on poultry. The rapid advance of biochemical and molecular tools has now made it possible to understand the molecular base of important phenotypic characteristics. Fats are the main storage source of energy in animal body with important role in cell membrane structure, gene regulation and precursors of important regulatory metabolites. From a functional point of view, it has been suggested that dietary fats change liver fatty acid synthesis and other lipogenic enzymes by regulating mRNA synthesis. Nuclear hormone receptors are defined as ligand-activated transcription factors which directly and indirectly regulate a number of genes involved in lipid metabolism and inflammatory signalling. The peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of transcription factors. PPARs are involved in cellular differentiation, insulin sensitisation, cancer, atherosclerosis and several metabolic diseases. Three distinct PPAR genes have been recognised as α, δ and γ. The most important metabolic effect of PPARγ is its role in adipogenesis. PPARγ is a central gene regulator in adipose tissue and stimulate the expression of several genes involved in adipogenesis. Based upon examples taken from chicken lipid metabolism, it is possible to draw lessons from the study of PPARγ functions in order to approach the study of gene expression PPARγ functions regulatory pathways interactions.