Abstract
Antarctica is an extreme environment for life.
The cold is an obviously challenging problem for life in
Antarctica, however, another is that Antarctica is very
dry. The availability of liquid water is recognized as the
most important determinant of the biological activity for
Antarctic organisms. Desiccation tolerance is as
important as cold tolerance for the survival of terrestrial
organisms in the Antarctic environments. This review
describes 1. Introduction to Antarctic animals, 2.
Antarctic environment for life and their tolerances, 3. A
tolerance gene, LEA, in animals.
1. We established a cultivation method for Antarctic
tardigrade and nematode, Acutuncus antarcticus and
Plectus murrayi, which have freezing and desiccation
tolerances. P. murrayi were recovered from 25.5 years of
storage at -20°C. They might tolerate freezing during
periodic short-term (several decades) glacial
advance-retreat cycles.
2. Animals survive low temperature in Antarctica by
freeze avoidance and/or freeze tolerance, with small
molecules such as sugar and sugar alcohols, and with
anti-freezing proteins. Under desiccation stress, animals
also produce small molecules like trehalose, and
protective proteins like LEA.
3. LEA proteins are rich in hydrophilic amino acids and
intrinsically disordered, however, they become
amphiphilic α-helix when dried. LEA proteins are
proposed to function in preventing protein-aggregation
by interacting with desiccation-sensitive proteins in a
dehydrated condition
