Identification of genes expressed in the liver of Japanese flounder Paralichthys olivaceus by expressed sequence tags

A list of genes expressed in the liver of Japanese flounder was compiled using an expressed sequence tag (EST) strategy; 940 EST derived from liver cDNA clones were determined. Bioinformatic analysis revealed that 537 (57%) of the EST could be ascribed to the transcriptional products of identified genes including 397 previously described in fish. The identified genes were classified with respect to a cellular role, which showed that 314 (58%) of the identified genes encoded proteins associated with primary liver functions such as transport, acute phase response, and blood clotting. Furthermore, comparative analysis revealed that 26 unique genes had homologous to known genes highly expressed in mammalian liver systems. cDNA clones corresponding to antimicrobial peptide origin in the mammalian liver, the hepcidin-like peptide, had conserved cysteine residues similar to the previously identified hepcidin-like peptide type 11 from winter flounder and were also found in Japanese flounder.