Tardigrades, perhaps more commonly known as water bears, are tiny creatures that maintain such strange characteristics. These Muppet-like creatures are able to survive extreme conditions, including staggering amounts of radiation, temperatures 302 degrees Fahrenheit to almost absolute zero, and pressures that would beat those in the deepest ocean trenches.
Water bears can also endure being dried up for up to a decade or even longer. In a new study, researchers found that they have special genes encoding for disordered proteins to help water bears survive near 100 percent water loss.
Extreme Desiccation: How Do They It?
Scientists previously assumed that this survival ability is due to a sugar called trehalose, which is what sea monkeys or brine shrimps use for preserving cells during desiccation. Trehalose levels, however, appeared much lower in water bears, so it couldn’t possibly be the key.
The team of Thomas Boothby at the University of North Carolina, Chapel Hill, discovered clues in the water bears’ genes.
"The big takeaway from our study is that tardigrades have evolved unique genes that allow them to survive drying out. In addition, the proteins that these genes encode can be used to protect other biological material — like bacteria, yeast, and certain enzymes — from desiccation,” explained Boothby, a postdoc fellow and the study first author, in a statement.
The team discovered that water bears produce a special kind of glassy substance holding their essential proteins and molecules in a suspended state until their bodies are rehydrated.
The glass practically traps desiccation-sensitive molecules in a form of matrix and hinder them from breaking like they usually would without the glassy protection, Boothby told Christian Science Monitor.
Proteins known as tardigrade-specific intrinsically disordered proteins (TDPs) are responsible for producing this “bioglass,” where the shapeless yet highly flexible rearrange into solid bioglass once extreme drying takes place.
Once the water bears are exposed to water again, the bioglass melts, and the unique proteins return to their old random state.
Engineering The Same Unique Proteins In Other Animals
The researchers figured out that they could also maneuver other creatures to carry the same proteins and survive extreme desiccation.
When they inserted the genes into living bacteria and yeast, they discovered that the proteins equipped them against extreme desiccation just like they did with water bears. TDPs in a test tube are deemed adequately protective of desiccation-sensitive molecules, physically barring their breakage or folding.
These results offer the exciting possibility that TDPs could also work the same wonders on larger and more complex animals.
Cellular biologist John Crowe told the Monitor that it’s a “convincing piece of research,” but he is hardly convinced that the disordered proteins are tardigrade-specific as suggested. The proteins may also turn up in other desiccation-tolerant organisms, he said.
Potential real-world uses and applications of TDPs include protecting crops from drought as well as allowing medications to be stored at room temperature instead of constantly chilled conditions. The latter could be a good development for supplying important drugs in remote communities or those that lack refrigeration.
In light of rising global temperatures and greater spread of disease, results like this may also spell greater chances of survival for a number of life forms.
The findings were discussed in the journal Molecular Cell.