Bioinformatics analysis and tissue-specific expression of intestinal-type fatty acid binding protein in domestic pigeons (Columba livia)

Intestinal fatty-acid binding protein (I-FABP, also called FABP2) is involved in the uptake of dietary fatty acids in the intestine, and its binding specificity is only with long-chain fatty acid. In this study, sequences of 4 exons in pigeon FABP2 were successfully amplified. The encoded protein had a molecular weight of 15.13 kDa and the theoretical pI was 6.75. Bioinformatics analysis indicated that the protein was predicted to contain 10 potential phosphorylation sites and did not contain signal peptide structure. The evolutionary analysis suggested the amino acid sequence of pigeon FABP2 was closest to the mallard (Nippoia nippon) homologs. Meanwhile the expression of FABP2 mRNA in different ages and tissues we conducted. It showed that the expression of the FABP2 gene was the highest in the liver, followed by the small intestine and adipose tissue, while lowest in the breast muscle. Also, the expression level in the gizzard was gradually increased with aging. Our results may serve as reference to better studies of the functional characterization and structure of the FABP2 in pigeon.