Tardigrades use protective protein to shield their DNA from radiation

The protective protein also protected DNA in genetically engineered human cells.

By Brooks Hays

An artistic rendering shows what a tardigrade, or water bear, looks like. Photo by Sebastian Kaulitzki/Shutterstock

 

Tardigrades are thought to be the most durable life form on Earth. The eight-legged, water-dwelling creatures can survive extreme temperatures, intense pressure and seemingly deadly levels of radiation.

New research reveals how the micro-animals -- sometimes called water bears -- protect their DNA from harmful ultraviolet rays.

Tardigrades are short and fat creatures stretching just half a millimeter when fully grown. They prefer wet environs and are especially common in mosses and lichens, where they feed on dead plant matter and small invertebrates. They're most closely related to nematodes.

A team of scientists at the University of Tokyo recently sequenced the entire genome of the tardigrade species Ramazzottius varieornatus. The results revealed a special protein responsible for shielding the creatures' DNA from harmful radiation.

Researchers named the protective protein Dsup, short for Damage Suppressor.

When scientists engineered human cells to produce the Dsup protein, the cells experienced significantly less radiation damage than unprotected cells when irradiated.

The scientists detailed their findings in a new paper published this week in the journal Nature Communications.

"What's astonishing is that previously, molecules that repair damaged DNA were thought to be important for tolerating radiation," study co-author Takuma Hashimoto explained in a news release. "On the contrary, Dsup works to minimize the harm inflicted on the DNA."

The protective power of Dsup is just the first of what of what scientists expect to be many revelations in the wake of the sequencing of the water bear's genome.

Scientists expect further research to reveal other genes and Dsup-like proteins key to the tardigrade's ability to survive being boiled, frozen and exposed to the vacuum of space, among other feats of hardiness.