Cryoprotective dehydration: clues from an insect

Arthropods have evolved a number of different adaptations to survive extreme environmental temperatures including, in some regions, over-wintering temperatures well below 0°C. One of the less common adaptations to surviving cold is that of cryoprotective dehydration, where the animal becomes almost anhydrobiotic with the loss of virtually all osmotically active water. In this chapter, we describe integrated studies utilising physiology, biochemistry and molecular biology to understand this phenomenon in the Arctic springtail (Megaphorura arctica) (formerly Onychiurus arcticus). These studies concentrate on the action of trehalose as a cryoprotectant, the production of antioxidants to reduce cell damage and changes in membrane composition.