For water bears, the glass is all full
When they dry out, tardigrades protect key body bits with orderly proteins
SAN DIEGO — Water bears turn into glass when they dry out.
That glazing enables the hardy microscopic creatures, also known as tardigrades, to withstand extreme desiccation, biologist Thomas Boothby of the University of North Carolina at Chapel Hill reported December 15 at the annual meeting of the American Society for Cell Biology.
Boothby and colleagues discovered that water bears make a lot of certain proteins in dry conditions. Those proteins are floppy and unformed when tardigrades are hydrated. As the animals dry, the proteins fold into a glasslike solid that encases and protects other proteins and molecules that would normally fall apart when dried. Adding water melts the glass and the tardigrade recovers. Yeast engineered to produce the tardigrade glass proteins survive desiccation better than they normally do, Boothby’s collaborators discovered.