Water bears can withstand 1,000 times more radiation than humans

When researchers from many institutions across China looked closely at the genome of the new tardigrade species Hypsibius Henanensis discovered 6 years ago, They found 14,701 protein-coding genes, of which 4,436 genes (30.2%) are unique to tardigrades. They also exposed the tiny animal to beams of radiation to monitor how gene expression and protein production would be affected, along with the biological superpowers these genes give the tardigrade. Science Alert reported on November 5.

“Research on several species of tardigrades has shown that they are the most radiation-resistant animals on Earth,” the research team shared in an article published in the journal Science. “They demonstrate resistance to gamma radiation from 3,000 to 5,000 grays (Gy), about 1,000 times the lethal level.”

The researchers made three key observations. First, a gene called ADD1likely transmitted by bacteria, produces betalain pigments that help neutralize harmful molecules created by radiation. Second, DNA is repaired much faster than usual thanks to a protein found only in tardigrades called TRID1. Third is the increased production of two other proteins, BCS1 and NDUFB8 (which help provide energy).

Careful analysis of H. henanensis provides further details that reveal how tardigrades live so long. Combined, all three factors help protect tardigrades against the dangerous effects of radiation. The next step is to look at how these protections play out across all tardigrade species.

Researchers know of 1,500 species of water bears. Water bears are believed to have first appeared before the Cambrian period about 541 million years ago. Their ability to survive the harshest conditions continues to change our definition of the limits of animals on Earth. Water bears’ radiation resistance genes have great potential for applications in the fields of health, space exploration, agriculture and medicine. By studying how tardigrades protect themselves against radiation, scientists can develop new materials and technologies to help astronauts avoid the harmful effects of space radiation on the Moon.

The Moon has no atmosphere to protect against harmful radiation from the Sun, especially during solar flares. The Moon is also bombarded by cosmic rays, high-energy particles from distant galaxies. Without protection, they can penetrate the human body and cause cell damage. Water bears could pave the way to many biotechnological achievements that benefit astronauts, such as developing drugs to help deal with the effects of cosmic radiation or gene editing techniques to enhance human endurance.