Cloning of fatty acid-binding protein 2 (fabp2) in loach (Misgurnus anguillicaudatus) and its expression in response to dietary oxidized fish oil.

Fatty acid-binding protein 2 (FABP2) is involved in the uptake of dietary fatty acids and intracellular fatty acid transport. In the present study, cDNA of fabp2 in loach (Misgurnus anguillicaudatus) was cloned and its full length was 956 bp, encoding 134 amino acids. Gene expression of fabp2 was investigated in different development stages and different tissues of loach, showing that the expression of fabp2 was recorded at 2 days after hatching (DAH), 10DAH, 20DAH and 35DAH, and higher in loach intestine, muscle and brain, compared with other tissues. We also investigated the effects of dietary oxidized fish oil (OFO) on the expression of intestinal fabp2 in loach juveniles by using fluorescence in situ hybridization (FISH) and real-time quantitative PCR. Fabp2 gene was expressed mainly by the intestinal epithelium cells of loach juveniles. The expression of intestinal fabp2 in loaches fed with OFO diet was significantly up-regulated on day 1 and 3, and down-regulated on day 10 after feeding, compared with those loaches fed with dietary fresh fish oil (FO), which were in accordance with the fluorescence intensities of FISH exhibiting in the corresponding feeding time. The present study indicated that dietary oxidized fish oil could affect the expression of fabp2 in the loach. Our results serve as reference to better understand the functional characterization of fabp2 in loach and other fish species.