The project funded by this ARO grant is to characterize genes that are responsible for the physiological changes that occur during hibernation in the heart of the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). We focused on the heart because it is a contractile organ that must continue to work despite physiological conditions that would be lethal to most mammals. We used a PCR-based gene expression screen to isolate cDNAs of genes ...
Hibernation in mammals requires a metabolic shift away from the oxidation of carbohydrates and toward the combustion of stored fatty acids as the primary source of energy during torpor. A key element involved in this fuel selection is pyruvate dehydrogenase kinase isoenzyme 4 (PDK4). PDK4 inhibits pyruvate dehydrogenase and thus minimizes carbohydrate oxidation by preventing the flow of glycolytic products into the tricarboxylic acid cycle. This paper examines expression of ...
We have successfully identified genes controlling the physiological characteristics of hibernation in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). Identification of these specific genetic markers has allowed us to study the function of their gene products under highly controlled conditions of temperature, light and humidity. To accomplish this goal specific instrumentation was purchased with this DURIP grant. Measurements of low-temperature physiology in hibernating mammals under controlled conditions required an environmental chamber ...
During hibernation, mammals rely heavily on lipid stores to provide the fuel necessary to survive the winter. Pyruvate dehydrogenase kinase isozyme 4 (PDK4) plays a key role in gating carbohydrate catabolism and allowing the switch to lipid metabolism. Earlier we reported that PDK-4 was up- regulated in the heart of the thirteen-lined ground squirrel during hibernation. PDK-4 is encoded by the nuclear genome and acts by phosphorylating pyruvate dehydrogenase (PDH) ...
We have successfully identified genes controlling the physiological characteristics of hibernation in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus). Identification of these specific genetic markers has allowed us to study the function of their gene products under highly controlled conditions of temperature, light and humidity. To accomplish this goal specific instrumentation was purchased with this DURIP grant. Measurements of low-temperature physiology in hibernating mammals under controlled conditions required an environmental chamber ...
Hibernating mammals provide a unique system for identifying molecules important in regulating metabolism, body temperature, and sleep. In a state of deep hibernation, body temperature is only a few degrees above 0 deg C and heart rate can be as low as 3-10 beats/min, compared to 200-300 beats/min when the animal is awake and active. We have identified genes that are responsible for regulating the physiological characteristics of hibernation in ...
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