Scientists have learned how the most tenacious creatures on Earth survive “drying”
MOSCOW, 16 Mar — RIA Novosti. The famous tardigrades, animals that can live in space and carry a huge dose of radiation, are able to come back to life after they have been fully “drying” due to the presence in their body special proteins that protect them from death in total absence of water, according to a paper published in the journal Molecular Cell.
“The main conclusion of our study — the animals have unique genes that allow them to survive complete desiccation. These genes and their associated proteins can be used to protect other organisms and biomaterials, for example, bacteria, yeast, or certain drugs, death, or decay,” said Thomas Boothby (Thomas Boothby) from the University of North Carolina at chapel hill (USA).
In 2007, scientists made a surprising discovery when analyzing data collected by the Russian spacecraft “Foton-M3”:
it turned out that tardigrades are small invertebrates, distant relatives of crabs and insects are able to survive for a very long time in open space and even multiply in conditions of complete weightlessness and the lack of food and water.
When scientists began to calculate and study the genes of animals, they expect a big surprise — more than 6.5 thousand of DNA from 38 thousand genes (18%) were “borrowed” from other organisms. Most of them were obtained from bacteria-the extremophiles, but in the genome of animals as there are genes of plants, fungi and archaea. Recently, scientists have discovered that cells of animals contain unique proteins that protect them from lethal doses of radiation.
Boothby and his colleagues have added to the number of such “miracle protein” another set of very exotic molecules, protecting the animals from death in the complete disappearance of water from their environment and from their cells and tissues.
As noted by Boothby, scientists had thought that tardigrades use a special sugar molecules “freeze” their insides to protect from death during the desiccation, however their experiments have shown that it’s actually not.
Many species of animals that can exist in dried form for decades, do not contain these sugars, but they can survive many cycles of “complete dry” with no visible harm to health.
Trying to uncover the mystery of their survival, Boothby and his colleagues tracked which genes were activated in the cells of animals during desiccation and revival. As it turned out, at such moments, life was most active genes CAHS, SAHS and MAHS responsible for the Assembly of very strange molecules — so-called internally disordered proteins.
They differ from most other protein molecules because they do not have a clear three-dimensional structure and may take arbitrary shape. This feature, as the scientists explain, allows these proteins to turn into a kind of “glass” in the disappearance of water, but not in the crystals, as do the normal proteins, and to protect the inside of the cell from damage.
A simple transplant of genes responsible for the Assembly of these molecules in a glass of proteins, transfers to other organisms ability to survive a “complete drying”. At the moment, the researchers tested their work on bacteria and yeast, however they believe that the proteins of animals can be used to create plants that can survive drought, and “drying” of liquid drugs and vaccines.
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