Cloning and tissue expression of chicken heart fatty acid-binding protein and intestine fatty acid-binding protein genes.

Fatty acid-binding proteins (FABPs) are members of a superfamily of lipid-binding proteins, occurring intracellularly in invertebrates and vertebrates. This study was designed to clone and characterize the genes of heart fatty acid-binding protein and intestine fatty acid-binding protein in the chicken. PCR primers were designed according to the chicken EST sequences to amplify cDNA of H-FABP and I-FABP genes from chicken heart and intestinal tissues. Analysis of sequence showed that the cDNA of the chicken H-FABP gene is 75 to 77% homologues to human, mouse, and pig H-FABP genes, and the chicken I-FABP gene is 71 to 72% homologues to human, mouse, and pig I-FABP genes. In addition, Northern blot analysis indicated that of the two genes, similar to the copartner of the mammal, H-FABP gene was expressed in a wide variety of tissues, and I-FABP gene was expressed only in intestinal tissues. The expression levels of the chicken H-FABP mRNA in heart and I-FABP mRNA in intestine had significant differences between the broilers from fat line and Bai'er layers at six weeks of age. The results of this study provided basic molecular information for studying the role of two FABPs in the regulation of fatty acid metabolism in avian species.