Anhydrobiotic abilities of tardigrades

Abstract

Tardigrades have been discovered in 1773 and are found in a variety of habitats within marine, freshwater, and terrestrial ecosystems. To survive in habitats that are prone to occasional drought, they possess the ability to enter a reversible state known as anhydrobiosis. The desiccation tolerance allows them to cope with temporal variation of available water and extended lifespan in an anhydrobiotic state with up to 20 years by producing a time shift in the age of tardigrades. The period of anhydrobiosis is limited by cumulative DNA damage and the function of repair pathways during and after rehydration. The same pathways are probably responsible for the tolerance of high doses of radiation. Heat shock proteins serve as molecular chaperones to preserve or restore the protein integrity and late embryogenesis abundant (LEA) proteins LEA proteins play an important role as well. In several desiccated species glass transition has been detected, which support the vitrification hypothesis. © 2010 Springer-Verlag Berlin Heidelberg.