Gene expression of fatty acid binding protein genes and its relationship with fat deposition of Thai native crossbreed chickens.

Objective: The objectives of this study were to investigate the relationship between the mRNA expression of Adipocyte type Fatty Acid Binding Protein (A-FABP) and Heart type FABP (H-FABP) in Thai native chicken crossbreeds and evaluate the level of exotic inclusion in native chicken that will improve growth while maintaining its relatively low carcass fat. Methods: The fat deposition traits and mRNA expression of A-FABP and H-FABP were evaluated at 6, 8, 10 and 12 weeks of age in 4 chicken breeds (n=8 /breed/week) [100% Chee breed (CH) (100% Thai native chicken background), CH male and broiler female (Kaimook e-san1; KM1) (50% CH background), broiler male and KM1 female (Kaimook e-san2; KM2) (25% CH background), and broiler (BR)] using abdominal fat and muscular tissues. Results: The BR breed was only evaluated at 6 weeks of age. At week 6, the CH breed had a significantly lower A-FABP expression in abdominal fat and intramuscular fat compared with the other breeds. At 8-12 weeks, the KM2 groups showed significant upregulation (P<0.05) of A-FABP in both ABF and IF compared to the CH and KM1 groups. The expression of H-FABP did not follow any consistent pattern in both Abdominal fat (ABF) and Intramuscular fat (IF) across the different ages. Conclusion: Some level of crossbreeding CH chickens can be done to improve growth rate while maintaining their low abdominal and intramuscular fat. The expression level of A-FABP correlate with most fat traits. There was no consistency of H-FABP expression across breed. A-FABPs is involved in fat deposition, genetic markers in these genes could be used in marker assisted studies to select against excessive fat accumulation.