Abstract：In order to investigate the differences of hepatic lipid synthesis between fat and lean lines of broiler chickens, the gene expression levels of acetyl CoA-carboxylase (ACC), fatty acid synthase (FAS), sterol regulatory element binding protein-1 (SREBP1), liver X receptor (LXR), glycerophosphate acyltransferase (GPAT), apoprotein A-1 (ApoA-1), glucose transporter (GLUT2) and apoprotein B (ApoB) genes were analyzed in livers of the 14th generation of Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) population using Real-time RT-PCR. The results revealed that, the expression levels of ACC, FAS, SREBP1, LXR, GPAT and ApoA-1 genes, on the whole, were higher in fat line than that in lean line. In particular, the expression levels of ACC, FAS and SREBP1 genes were dramatically higher in fat line than that in lean line at the age of 10 weeks (P<0.01). In addition, the expression of LXR gene was significantly higher in fat line than that in lean line at the age of 9 and 10 weeks (P<0.01), and the expression of ApoA-1 gene was significantly higher in fat line than that in lean line at the age of 6, 8, 10, and 11 wk (P<0.01 or P<0.05). However, the expression of GLUT2 gene was significantly higher in lean line than in fat line at the age of 5 and 8 weeks (P<0.05), and the expression of ApoB gene was also significantly higher in lean line than that in fat line at the age of 7 weeks (P<0.05). Taken together, these results suggested that fat broilers have higher a capacity for hepatic fat synthesis than that of lean broilers, which may lead to divergent phenotype for fatness traits. Our findings provide basic research material for further study on the molecular mechanisms of broiler fatness traits.
