Natures wonders: waterbears dry survival (Introduction)

by David Turell , Sunday, March 19, 2017, 21:00 (2804 days ago) @ David Turell

These tiny animals dry themselves out to survive almost everywhere:

http://www.theatlantic.com/science/archive/2015/11/tardigrades-worlds-toughest-animals-...

Further reading:-http://www.nature.com/nrg/journal/v16/n8/abs/nrg3962.html

The latest findings in how they do it:

http://www.livescience.com/58309-how-tardigrades-survive-drying.html

"Tardigrades live on damp moss and algae around the world. Researchers have found that tardigrades can withstand searing heat and freezing cold, up to 300 degrees Fahrenheit (149 degrees Celsius) and as low as minus 328 degrees Fahrenheit (minus 200 degrees Celsius). Tardigrades can even emerge unscathed after exposure to boiling, high pressure, and the radiation and vacuum of space.

"The creatures survive by expelling the water from their bodies and entering a suspended state known as a "tun." During this state, they retract their limbs and shrink into tiny, desiccated balls, emerging only when life-threatening conditions have passed. But scientists have wondered how that was possible, particularly for tardigrades that spend a decade or more as dried-out tuns.

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"Results showed that certain genes were expressing a type of protein unique to tardigrades, which the scientists dubbed tardigrade-specific intrinsically disordered proteins, or TDPs. In some species of tardigrades, the genes that produce TDPs were active all the time, while in other species, these genes were activated only under certain conditions.

"TDPs protected the tardigrades in much in the same way that trehalose protects other animals, by forming glass-like structures that help to preserve cells that are in a dehydrated state.

"The tardigrade species that had a constant supply of TDPs was more successful at recovering from drying out than the species that weren't always producing TDPs, the researchers wrote.

"'We think it can do this because it has so many of these proteins around already and doesn't need time to make them," study lead author Thomas C. Boothby, a Life Sciences Research Foundation Postdoctoral Fellow at the University of North Carolina, said in a statement.

"The findings reveal that biological methods used to tolerate environmental stress and withstand desiccation are more diverse than suspected, the researchers said."

Comment: they are much like spores or seeds stored for a long time that can come to active life. It is hard to imagine how this ability developed. If it didn't worked from the beginning of drying out, they would not have survived. Suggests salation.