Electronic Thesis and Dissertation Repository


Master of Science




Dr. James F. Staples


Hibernation in mammals involves a suppression of metabolic rate thereby conserving energy. Many hibernation studies focus on the mitochondria due to their energy-producing role. I hypothesized that this pattern of rapid suppression of liver mitochondrial metabolism with gradual reversal, was related to changes in the phosphorylation state of Ictidomys tridecemlineatus’ mitochondrial proteins in different stages of torpor bouts. Phosphorylation of threonine and serine amino-acid residues (unique to 49, 41 and 47, 38 kDa proteins respectively), detected using immunoblotting, changes seasonally (threonine: summer active > winter, serine: summer active > torpor), whereas no seasonal difference was observed in phosphotyrosine residues. Changes in protein phosphorylation among hibernation-specific metabolic stages do not correlate with mitochondrial respiration. Season-dependent differentially phosphorylated proteins were identified via MALDI-TOF/TOF MS (F1-ATPase α-chain, long-chain specific acyl-CoA dehydrogenase, ornithine transcarbamylase) and potential hibernation-specific roles are discussed.