Tardigrades can survive decades without water, and we finally know how: ScienceAlert

Water is an essential component of all life on Earth, yet it is tardigrades Close to immortal forces It can somehow withstand being depleted of all the H2s.

Now, researchers have discovered another trick these chubby microscopic anomalies use to survive Years of severe drought.

“Although water is essential to all life as we know it, some tardigrades can probably live without it for decades,” Says Biologist at the University of Tokyo Takekazu Konida.

Many of the thirteen species known as water bears are colloquially known tardigrades It tolerates conditions that would be fatal to all other known forms of life.

starve them, boil themAnd the Freeze themAnd the radiate themor Shoot them with a pistol and these Velvet worm distant relatives Will keep coming back for more.

When these aquatic animals find themselves in a see-through environment, tardigrades wither into a round shape called Ton.

As Koneda and fellow University of Tokyo biologist Akihiro Tanaka and colleagues explain in their paper, dried tardigrades are exceptionally stable and can tolerate many extremes including Exposure to the vacuum of space They are still able to revive themselves.

“It is thought that as the water leaves the cell, a type of protein must help the cell maintain its physical strength to avoid collapsing on itself.” Says Canada.

So, the researchers combed a group of tardigrades known for their ability to dehydrate called eutardigrades for proteins that could explain the phenomenon, and found 336 unique suspects.

“After testing several different types, we found that the cytoplasmic heat-soluble proteins (CAHS), which are unique to tardigrades, are responsible for protecting their cells from drying out.” explain.

Using experiments on human and insect cells, the researchers were able to demonstrate that CAHS proteins increase cell stiffness, supporting the cell against shrinkage caused by lost water pressure. The proteins even protect cells from excessive water pressure, too.

“Trying to learn how CAHS proteins function in human and insect cells presents some interesting challenges,” Says Tanaka.

“A typical staining method requires solutions that contain water, which obviously confuses any experiment where water concentration is a factor one seeks to control. So we resorted to a methanol-based solution to get around this problem.”

This allowed them to see the CAHS proteins at work inside the cells grown in the lab.

The uniform green oscillating liquid unites into filamentous filaments.
The filament-forming CAHS proteins are dried as a cultured human cell. (A Tanaka and T Kunieda)

CAHS proteins appear to function as cellular scaffold structures similar to cell proteins cytoskeleton – but only when cells experience the stress of water loss.

As shown in the video above, CAHS proteins in dehydrated cells bind together to form spider webs of supportive filaments, providing an on-demand transition into this filament-like, gel-like phase.

The cytoskeleton-like structures protect the cell from complete deformation due to lack of water pressures and likely contribute to the amazing stability of tones.

This process, called anhydrobiosis, can be reversed to allow tardigrades to pick up their lives where they left off, and once again hydration conditions return.

Scientists previously suspected a protein-based “bioglass” that keeps tardigrades’ cellular structures intact during severe dehydration.

However, previous studies only looked for The genetic components of this ability; This new study looked for actual proteins.

Stylish biological tricks like this allowed it eight legsyet still somehow adorable, animals reach all corners of our planet – from the scorching volcanic vents and crushing pressure of the depths of our oceans to tropical forests and icy tundra.

“Everything about tardigrades is awesome,” Says Canada.

“The extreme range of environments in which some species can survive leads us to explore unprecedented mechanisms and structures. For a biologist, this field is a goldmine.”

Other unique proteins isolated by Tanaka and colleagues may provide further clues to how tardigrades manage all of their impressive feats.

This research was published in Biology Plus.

Leave a Comment