Molecular characterization of myostatin in black seabream, Acanthopagrus schlegelii.

Myostatin is a negative regulator of skeletal muscle growth and has a potential application in aquaculture. The black seabream myostatin gene was cloned and sequenced. It had three exons encoding a protein of 382 amino acids. A 90 bp 5'-untranslated region (UTR) and a 536 bp 3'-UTR were obtained by RACE. Four microsatellite sequences, a (CAG)9, a (TC)12, a (CA)16 repeat and an "imperfect" (CA)25 microsatellite, were found in the myostatin. Two introns were 329 and 742 bp in length, respectively. The deduced amino acid sequence of the myostatin had a putative amino terminal signal sequence, a TGF-beta propeptide domain, a RXXR proteolytic processing site, a TGF-beta domain, and 12 conserved cysteine residues. The myostatin gene was expressed in four of the examined ten tissues and organs. The expression of myostatin was the strongest in the skeletal muscle and brain, intermediate in the eye, and low in the heart.