Differential expression of L-FABP and L-BABP between fat and lean chickens

Liver fatty acid-binding protein (L-FABP) and liver bile acid-binding protein (L-BABP), in the liver intra-cytoplasm of chicken, are members of the fatty acid-binding protein subfamily. This study was designed to analyze and compare L-FABP and L-BABP expression levels between fat and lean lines in chicken liver tissue, and to determine the relationship between their expression and lipid metabolism. Real-time polymerase chain reaction (PCR) and Western blotting were used to detect the mRNA and protein expression in liver tissue between the lean and fat lines. Real-time PCR showed that L-FABP mRNA expression in fat male chickens was higher than that in lean male chickens at 2, 3, 4, 5, 6, and 10 weeks of age (P < 0.05), and L-BABP mRNA expression in fat male chickens was higher than that in lean male chickens at 1, 2, 3, 4, 8, and 10 weeks of age (P < 0.05). Western blotting showed that the L-FABP protein expression in fat male chickens was higher than that in lean male chickens at 3, 5, 6, and 7 weeks of age (P < 0.05), and L-BABP protein expression in fat male chickens was higher than that in lean male chickens at 3, 4, 5, and 6 weeks of age (P < 0.05). These results suggested that chicken L-FABP and L-BABP affect abdominal fat deposition through differences in their expression level, and the possible mechanism is that a high expression level of L-FABP and L-BABP leads to a high lipogenesis rate and, ultimately, to lipid deposition.