Abstract
Anhydrobiosis (“life without water”) represents an extreme example of tolerance adaptation to water loss,
where an organism can survive in an ametabolic state until water returns. The sleeping chironomid
Polypedilum vanderplanki inhabiting in semiarid region of Africa is the only insect known to be capable of
anhydrobiosis. In the dehydrated larvae, massive accumulated trehalose is thought to replace the water in its
tissues. Simultaneously, highly hydrophilic proteins called the late embryogenesis abundant (LEA) proteins
are expressed in huge quantities and act as a molecular shield to defend other proteins and cell membranes
against aggregation and denaturation. Trehalose together with LEA proteins forms a glassy matrix, which
protects the biological molecules and maintains the structural integrity of larvae in the anhydrobiotic state.
Meanwhile, reparation factors are likely to be involved in the anhydrobiosis. Recently the draft genome
analysis of this insect has been accomplished. We determine that the genome of the sleeping chironomid
specifically contains clusters of multi-copy genes encoding desiccation protectants and reparation factors.
Here, we summarized recent topics on the molecular mechanisms underlying the anhydrobiosis in P.
vanderplanki.
