Scientists Find Out How Tardigrades Resist Radiation Bursts
Tardigrades may be the most resilient creatures on our planet. These tiny microorganisms can resist nearly any challenge humans present to them, emerging unscathed as they stroll along on their eight short legs.
The tactics facilitating these remarkable feats of superheroic survival are diverse. They range from a protective protein that shields their DNA from harm to a state of suspended animation called “tun,” in which they dehydrate themselves, enabling them to endure extreme external conditions.
New Discoveries in Tardigrade Radiation Resistance
And now researchers have found another one. They can set the damage restoration to maximum intensity.
A group of scientists, led by biologist Courtney Clark Hachtel of the University of North Carolina at Ashton, exposed tardigrades to gamma radiation and observed the animals’ reactions.
Bob Goldstein, a scientist at The University of North Carolina at Chapel Hill, adds, “What we saw startled us.” The tardigrades are acting in a way that surprised us.
For many years, we have known about tardigrades’ fantastic ability to withstand ionizing radiation. Moreover, they may carry on with their meager existence as if nothing had happened, surviving a dose that would be fatal to humans by a factor of 1,000. Additionally, their resilience is truly remarkable, considering the extreme conditions they can endure.
For certain tardigrade species, this is assumed to be due in part to the damage suppression protein Dsup; however, not all tardigrade species possess Dsup or a homolog thereof, indicating that alternative ways of survival may be involved.
To ascertain the cause, the scientists examined the impact of gamma radiation on the tardigrade Hypsibius exemplaris species. They subjected tardigrades to gamma rays released by the beta decay of cesium-137 by placing the animals in a tabletop irradiator. Because the amount of radiation is known, they were able to subject the tardigrades to two distinct doses—one lesser dosage that is within tolerated limits and another considerably greater median lethal dose.
To their astonishment, radiation exposure did not appear to cause H. exemplaris’s Dsup. The tardigrades’ DNA indeed suffered significant damage due to radiation.
Tardigrades DNA Repair Mechanisms Unveiled
Instead of providing preventive defense, the tardigrades increased the synthesis of DNA repair genes to the point that their byproducts are among the most prevalent in their tiny bodies. By the time they were 24 hours post-exposure, the majority of the ionizing radiation-damaged DNA in the tardigrades had been repaired.
In a subsequent study, the scientists exposed bacteria samples to ionizing radiation. They produced some of the tardigrade repair genes in an Escherichia coli cell. In contrast to untreated E. coli, bacteria implanted with tardigrade genes exhibited a DNA repair capacity akin to that of H. exemplaris.
The researchers deduced from this that H. exemplars might be able to detect ionizing radiation and establish a defense mechanism that enables it to withstand amounts of radiation that would ultimately destroy other creatures.
Implications for Radiation Protection Technology
Clark-Hachtel mentioned that the animals were mounting an incredible response to radiation, indicating that it appeared to be a secret to their exceptional survival abilities. Furthermore, she noted that their findings about how tardigrades overcome radiation stress could potentially inspire new approaches to protecting other animals and microorganisms from harmful radiation. In essence, their research sheds light on possibilities for improving radiation resistance in various organisms.
Considering that an animal can withstand a shot with a pistol, what more could one ask for?
Read the original article on: ScienceAlert
