Meeting Abstract

P1.79  Sunday, Jan. 4  A novel down-stream target of myostatin: important in muscle growth and regulation? BRASCHAYKO, E. B.; GALT, N. J.*; BIGA, P. R.; North Dakota State Univ.; North Dakota State Univ.; North Dakota State Univ. Elizabeth.Braschayko@ndsu.edu

Myostatin (MSTN) negatively regulates muscle growth in mammals, with some evidence in support of a similar role in fish. MSTN levels have been shown to be down-regulated in response to growth hormone and up-regulated during fasting in both giant danio (Danio aequipinnatus) and rainbow trout (Oncorhynchus mykiss). These data support a role of MSTN in fish growth. The intent of this project was to isolate and identify a potential downstream target of MSTN in muscle tissue. By utilizing the zebrafish (Danio rerio) genome and rainbow trout EST databases, a novel target, mighty was virtually cloned from rainbow trout and zebrafish. Utilizing degenerate primers, we subsequently isolated, empirically cloned, and sequenced mighty from the giant danio. Semi-quantitative and real-time PCR demonstrate similar tissue distribution between mighty and MSTN gene expression in adult giant danio. In addition, it has been demonstrated that mighty gene expression is down-regulated during fasting, while MSTN is up-regulated, suggesting an interaction in regulation of growth and metabolism. We hypothesize a regulatory interaction between MSTN and mighty, with opposing growth functions.