This project explores mechanisms of freeze tolerance, a remarkable adaptation by which select organisms can survive extreme cold by tolerating the freezing and thawing of their blood and other tissues. The model organism in these studies is the wood frog (Rana sylvatica), a North American amphibian whose habitat ranges from the Southern Piedmont north to within the Arctic Circle. Although freeze tolerance in this species was reported nearly 30 years ago, only recently was it discovered that frogs adapted to the subarctic climate are considerably more cold hardy than ones from more southerly locales.
The investigators will characterize fully freeze tolerance in frogs from Interior Alaska, comparing their physiological responses to freezing with those exhibited by frogs from a well-studied population in southern Ohio. Biochemical and molecular approaches will be used in laboratory experiments designed to detect unique adaptations of the cryoprotectant system and cell membrane that contribute to enhanced freeze tolerance in the Alaskan frogs. The outcomes of this research will improve the understanding of the evolution and physiological mechanisms of freeze tolerance, an important cold-hardiness strategy employed by diverse organisms. They may also suggest new approaches and tools for cryopreserving biological materials and offer insights into certain disease states, such as chronic pancreatitis and diabetes/obesity. In addition, enhancing understanding the winter biology of amphibians may help predict consequences of climate change for their long-term survival.
This project will enhance scientific and technological understanding by creating a traveling exhibit, "Nature's Frozen Marvels," to educate the general public about the fascinating adaptation of natural freeze tolerance, drawing special attention to the underlying biological, chemical, and physical principles. The investigators will work closely with the Hefner Zoology Museum staff at Miami University to plan and implement a special-topic course that will engage undergraduate students drawn from a variety of academic disciplines in designing the exhibit.
