Water bears: Unveiling the secrets of their radiation shield
Water bears are considered some of the most resilient creatures in the world. They can endure extreme conditions, including no water for 100 years. Surprised by their findings, scientists have uncovered the reasons why water bears can withstand strong radiation.
Tardigrada, or a type of very small invertebrates, whose body length ranges from about 0.1 to 1.3 millimetres, have long captivated many scientists. This interest is primarily due to their ability to survive under remarkably harsh conditions. Recent research reveals that water bears can endure temperatures of up to 150 degrees Celsius. They also withstand high pressure exceeding 6,000 bar and can survive without water for 100 years. Moreover, there is evidence to suggest that numerous (as there are over 1,000 species) water bears can survive in space.
Organisms resistant to radiation
Recent studies, the findings of which were published in the journal "Current Biology," focus on the survivability of water bears against radiation. These creatures display an exceptional ability, as water bears withstand radiation with an intensity 1,000 times greater than the lethal dose for humans. Researchers have discovered that Tardigrada have developed a mechanism to repair damage caused by exposure to radiation.
Until now, researchers speculated that some species of water bears had an extraordinary resilience to ionizing radiation because of a protein that inhibits DNA damage (Dsup). However, this protein, unique to water bears, is not found in all species, leading biologists to conclude that a different mechanism facilitates protection against radiation.
For their research, they used the species Hypsibius exemplaris, which contains Dsup. It was exposed to radiation in doses much higher than the lethal dose. The outcome was surprising for the scientists.
– What we saw surprised us. Water bears function in a manner unexpected to us – said Bob Goldstein from the University of North Carolina at Chapel Hill.
The DNA of Hypsibius exemplaris, subjected to extreme tests, was significantly damaged. Researchers observed that water bears can significantly increase the production rate of genes responsible for DNA repair. Within a short period, these genes become the most abundant in the bodies of the studied organisms, and within 24 hours of extreme exposure, water bears can repair most of the damaged DNA.
The findings also show that these microscopic creatures can somehow detect ionizing radiation and immediately initiate a defensive response in their bodies. The latest discoveries may help develop mechanisms to protect animals from harmful radiation in the future.
