Messenger RNA levels and transcription rates of hepatic lipogenesis genes in genetically lean and fat chickens.

Levels of body fat content in commercial meat chickens have prompted research in order to control the development of this trait. Based on experimentally selected divergent lean and fat lines, many studies have shown that liver metabolism has a major role in the fatness variability. In order to identify which genes are involved in this variability, we investigated the expression of several genes implicated in the hepatic lipid metabolism. The studied genes code for enzymes of fatty acid synthesis [ATP citrate-lyase (ACL), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME), stearoyl-CoA desaturase (SCD1)], for an apolipoprotein [apolipoprotein A1 (APOA1)], and for the CCAAT/enhancer binding protein alpha (C/EBPalpha), which is a transcription factor implied in the regulation of several genes of lipid metabolism. The results show that the fat-line chickens display significantly higher hepatic transcription rates and mRNA levels than the lean-line chickens for the ACL, ME and APOA1 genes. This suggests that these genes could be responsible for the phenotypic fatness variability.