Environmental Adaptations: Desiccation Tolerance

Abstract

Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires extreme adaptations. Antonie van Leeuwenhoek was the first who describe the phenomenon of the resurrection of a desiccated rotifer in 1702. As with some rotifers and other small organisms, tardigrades enter a desiccated state known as anhydrobiosis to withstand such environmental conditions. This allows them to cope with the temporal variation of available water and to extend their lifespan in an anhydrobiotic state by up to 20 years without biological aging, according to the Sleeping Beauty hypothesis. Heat shock proteins serve as molecular chaperones to preserve or restore protein integrity, and tardigrade-specific intrinsically disordered proteins (TDPs) as well as metabolite help prevent the formation of damaging cellular compartments aggregates during water stress.