Cloning and functional study of fatty acid-binding protein-like gene of the ridgetail white prawn, Exopalaemon carinicauda

Abstract

On the basis of transcriptome sequences, the fatty acid-binding protein (FABP) gene of Exopalaemon carinicauda was obtained by rapid amplification of cDNA ends (RACE) and named FABP. The full length of the FABP gene is 878 bp, with the open reading frame being 399 bp and the non-coding regions of the 5′ end and the 3′ end being 94 bp and 385 bp, respectively. The gene encodes a protein composed of 132 amino acids. A homology analysis showed that the FABP gene has high similarity with fatty acid-binding protein and retinoic acid-binding protein genes. Real-time PCR showed that the FABP gene was expressed mainly in subepidermal adipose tissue, and secondarily in intestine and heart. The expression characteristics at different developmental stages showed that the expression of the gene was low at the larval stage (0–25 d) and reached the highest level after 30 days. RNA interference results showed no significant difference in the appearance of E. carinicauda and no individual death after this gene was silenced. Compared with the control group, except C20:2n-6 which increased, the contents of the other 12 fatty acids in shrimps in the RNA interference group decreased significantly, and the total amount of fatty acids also decreased significantly, which suggests that the FABP gene is closely related to changes in fatty acid content in shrimp.