FROZEN ALIVE: The Winter Life of Frogs & Turtles

Freeze tolerance is the key to winter survival for many cold-blooded animals in Canada including various frogs and turtles and many kinds of insects. Many animals can survive for weeks with 65% of total body water frozen in extracellular ice masses. My lab uses genomic, proteomic and enzymatic technologies to identify the biochemical adaptations that support freezing survival, especially in the wood frog Rana sylvatica. Well -studied mechanisms of freeze tolerance include high levels of carbohydrate cryoprotectants and effective ice management. New work has found that many other aspects of cell preservation are also critical including ischemia protection, antioxidant defenses, cell volume regulation, freeze-specific gene expression, protein chaperones and metabolic arrest. Our work in understanding both cryoinjury and cryopreservation has key applications for the development of human organ cryopreservation.