Meeting Abstract

P3.116  Wednesday, Jan. 6  Acute Stress Differentially Affects Myostatin Expression in Rainbow Trout, Oncorhynchus mykiss GALT, Nicholas*; BILLING, Samantha; BIGA, Peggy; North Dakota State University Nicholas.Galt@ndsu.edu

Teleosts exhibit multiple myostatin (mstn) isoforms that are differentially regulated, suggesting that teleost mstn exhibits greater functional diversity. Mstn mRNA expression is found in a variety of tissues in rainbow trout (Oncorhynchus mykiss) when compared to its restricted muscular expression exhibited in mammals. We hypothesize that the gene expression of mstn1a and mstn1b will be affected when rainbow trout are handled to induce an acute stress, which is the result of a direct or indirect ability of mstn to partition energy towards physiological processes that are pertinent to the fitness of these fish. To determine the length of time needed for mstn mRNA levels to recover to pre-stress levels, we performed a time-series experiment where samples were collected out to 48hrs following a 60s handling stress. When handled, mstn1a mRNA levels significantly increased at all time periods from 0hrs to 9hrs, while mstn1b mRNA levels were significantly decreased from 0hrs to 9hrs. Interestingly, mstn1b mRNA levels are instantaneously decreased in both white (-29.75±1.62) and red (-228.94±16.25) muscle following handling stress, suggesting that mRNA stability is altered during this time. These data suggest mstn exhibits regulatory roles beyond what has previously been proposed, and evidence is supporting a critical role of mstn in energy partitioning in rainbow trout skeletal muscle. Future research will be conducted to elucidate the mechanisms by which mstn is being regulated and whether mstn is being acted on directly or indirectly by components of the stress response. Funded by ND EPSCoR # EPS0447679 and NIH NCRR # 2P20RR015566.