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Full-Text Articles in Animal Sciences
Circannual Patterns Of Adipose Tissue Characteristics In A Hibernator, The Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus), Amanda Maccannell
Circannual Patterns Of Adipose Tissue Characteristics In A Hibernator, The Thirteen-Lined Ground Squirrel (Ictidomys Tridecemlineatus), Amanda Maccannell
Electronic Thesis and Dissertation Repository
Obligate hibernators express circannual patterns of body mass and hibernation, which persist under constant laboratory conditions. I hypothesized that in the 13-lined ground squirrel (Ictidomys tridecemlineatus) thermogenic brown adipose tissue (BAT) and lipid storing white adipose tissue (WAT) volume would follow a circannual pattern. I housed animals at either 25°C (thermoneutral) or 5°C with 12h L:12h D photoperiods for an entire year. I determined volume and water-fat ratio of WAT and BAT using magnetic resonance imaging (MRI). BAT volume follows a circannual pattern in both conditions, increasing prior to winter, decreasing in late winter with no change in …
Regulation Of Liver Mitochondrial Metabolism During Hibernation By Post-Translational Modification, Katherine E. Mathers
Regulation Of Liver Mitochondrial Metabolism During Hibernation By Post-Translational Modification, Katherine E. Mathers
Electronic Thesis and Dissertation Repository
Hibernation, characterized by a seasonal reduction in metabolism and body temperature, allows animals to conserve energy when environmental conditions (e.g. temperature, food availability) are unfavourable. During hibernation, small mammals such as the 13-lined ground squirrel (Ictidomys tridecemlineatus) cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5 °C, and interbout euthermia (IBE), where metabolic rate and body temperature rapidly increase and are maintained at euthermic levels several hours. Suppression of metabolism during entrance into torpor is paralleled by rapid suppression of liver mitochondrial metabolism. In my thesis, I …
Changes In The Mitochondrial Phosphoproteome During Mammalian Hibernation, Dillon J. Chung
Changes In The Mitochondrial Phosphoproteome During Mammalian Hibernation, Dillon J. Chung
Electronic Thesis and Dissertation Repository
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 …
Mitochondrial Metabolic Suppression And Reactive Oxygen Species Production During Hypometabolism In Mammals, Jason Cl Brown
Mitochondrial Metabolic Suppression And Reactive Oxygen Species Production During Hypometabolism In Mammals, Jason Cl Brown
Electronic Thesis and Dissertation Repository
During hibernation, daily torpor, and fasting, mammals reduce metabolic rate (MR) up to 99%, 95%, and 30%, respectively, compared to resting levels. Mitochondrial metabolic suppression likely contributes to this MR reduction, and the first objective of this study was to determine the relative contributions of active, regulated inhibition and passive thermal effects as body temperature (Tb) falls, to mitochondrial metabolic suppression, and to examine the mechanisms involved using top-down elasticity analysis and novel statistical approach. The second objective of this study was to determine how mitochondrial metabolic suppression affects mitochondrial reactive oxygen species (ROS) production, a topic which …