Molecular cloning and functional analysis of the fatty acid-binding protein (Sp-FABP) gene in the mud crab (Scylla paramamosain)

intracellular fatty acid-binding proteins (fabps) are multifunctional cytosolic lipid-binding proteins found in vertebrates and invertebrates. in this work, we used race to obtain a full-length cdna of sp-fabp from the mud crab scylla paramamosain. the open reading frame of the full length cdna (886 bp) encoded a 136 amino acid polypeptide that showed high homology with related genes from other species. real-time quantitative pcr identified variable levels of sp-fabp transcripts in epidermis, eyestalk, gill, heart, hemocytes, hepatopancreas, muscle, ovary, stomach and thoracic ganglia. in ovaries, sp-fabp expression increased gradually from stage i to stage iv of development and decreased in stage v. sp-fabp transcripts in the hepatopancreas and hemocytes were up-regulated after a bacterial challenge with vibrio alginnolyficus. these results suggest that sp-fabp may be involved in the growth, reproduction and immunity of the mud crab.