Meeting Abstract

P2.82  Tuesday, Jan. 5  Effects of Molt Induction on Expression of a Myostatin-Like Protein in the Green Crab, Carcinus maenas CHO, I-G.*; COVI, J.A.; BADER, B.D.; CHANG, E.S.; MYKLES, D.L.; Colorado State University ilgyuesque@gmail.com

Myostain (Mstn), a member of the TGF-beta superfamily, is a negative regulator of muscle mass. In mammals, Mstn reduces mass by stimulating protein degradation and inhibiting protein synthesis. In crustaceans, a Mstn-like protein may regulate protein turnover in a reversible molt-induced muscle atrophy, which facilitates withdrawal of the claws during ecdysis. In land crab, molting causes a dramatic down-regulation of Mstn associated with increased protein synthesis. We hypothesize this increased turnover is required for remodeling of the contractile apparatus as fibers are reduced in size. We have cloned a partial cDNA (872 bp) of a Mstn-like protein from green crab, Carcinus maenas, that is highly conserved with Mstn in the land crab, Gecarcinus lateralis (78% amino acid identity), and lobster, Homarus americanus (74% amino acid identity). The Cm-Mstn encodes the entire 114 mature peptide amino acid sequence and part of the propeptide sequence. Real-time RT-PCR is being used to quantify the effects of molting on Cm-Mstn expression in claw and thoracic muscles. Supported by NSF (IBN-0618203).