Scientists have made a breakthrough in understanding how tardigrades are able to survive in extreme conditions

Tardigrades are known for their ability to withstand extreme environments, and we now know how they do this. Small molecular sensors inside cells can detect when harmful molecules called free radicals are produced in excess, causing a state of dormancy.

Tardigrades, also known as tardigrades, are eight-legged microscopic invertebrates found throughout the world. Under adverse conditions such as sub-zero temperatures and strong radiation, the creatures shrink into a dry ball called a tongue and enter a deep hibernation state.

“Tardigrades do not breed under extreme conditions, but they can overwinter.” Derrick Colling At Marshall University in West Virginia. “We wanted to understand how they could step in there.”

To study, Kolling and colleagues exposed tardigrades to high levels of hydrogen peroxide, sugar, salt, or temperatures of -80°C (-112°F) to induce Tun. As a result of these stresses, tardigrades produce harmful, highly reactive molecules called oxygen free radicals.

The free radicals then go on to react with other molecules, team members say. leslie hix At the University of North Carolina at Chapel Hill. Importantly, the research team discovered that free radicals oxidize an amino acid called cysteine, which is one of the building blocks of proteins in the body. These reactions change protein structure and function and signal the onset of quiescence.

In experiments where cysteine ​​oxidation was prevented, tardigrades were unable to enter the tun state. “Cysteine acts like a kind of regulatory sensor,” Hicks says. “This allows the tardigrade to sense its environment and respond to stress.”

When conditions improved, the researchers discovered that the cysteine ​​was no longer oxidized and instructed the tardigrades to wake up from the tongue.

“Whether this is a universally conserved protection mechanism and whether this is conserved across tardigrade species is a really important question,” Hicks says. Her answers, she says, could help us better understand the aging process and how to make long-term space travel a reality.