Many people joke that if there was ever a nuclear holocaust, only cockroaches would survive the fallout, but it turns out that the pests would likely be joined at the end of the world by a microscopic neighbor called the tardigrade. Also known as the moss piglet or water bear, this micro-animal’s amazing genetic makeup could also hold the key to protecting humans from intense radiation in space.
Tardigrades live in water environments but are incredibly adapted to surviving sudden droughts. If their watery homes ever dry up, through a process called Tun formation they simply shrivel and fold themselves up before going into a suspended state. Able to withstand incredibly high temperatures, intense pressure, and even the effects of complete vacuums in their shriveled-up states, as soon as they come into contact with water again they simply rehydrate themselves.
Furthermore, the tardigrade’s adaption to extreme dehydration is thought to also provide them with a high tolerance against X-rays. Under normal circumstances, severe dehydration or radiation exposure tears an organism’s DNA apart, so scientists were naturally interested to discover how the resilient animals were able to endure the effects of intense radiation.
The working theory had always been that the tardigrade’s DNA was simply able to repair itself at a lightning fast pace after damaging exposure to radiation, but after taking a close look at the genome of one of the more than 1000 known species of tardigrades, the latest findings by a team of researchers suggest something else may be at play.
Scientists uncovered a protein unique to tardigrade DNA called Dsup, which acts as a damage protector by encasing the micro-animal’s DNA, thus acting as a shield against radiation and preventing damage from occurring. To examine how Dsup might be applied elsewhere, the team of scientists injected the Dsup gene into samples of human kidney cells. The treated cells and some untreated cells were then exposed to radiation in a carefully controlled setting and assessed for signs of damage. Kidney cells that had the Dsup gene on average sustained 40 percent less damage than the ones that did not have the benefits of the gene.
The study’s results have been hailed as a major breakthrough, and there still seems to be other elements of the creature’s genome yet to be discovered that will shine further light on its incredible resistance to radiation. This means that further studies may uncover more protective proteins that could benefit human cells in similar ways, and commenting on the finding, Ingemar Jönsson an evolutionary ecologist studying tardigrades at the Kristianstad University in Sweden, said:
“Protection and repair of DNA is a fundamental component of all cells and a central aspect in many human diseases, including cancer and ageing.. We are really just at the beginning of exploring the genetic treasure that the tardigrade genome represents.”
While there are potentially many applications for Dsup protein here on Earth, this unique cellular substance from tardigrades could help to further space exploration. One of the major dangers that astronauts face when they travel through the solar system is exposure to intense radiation, as evidenced by the robust radiation shielding requirement of unmanned space vessels. Scientists, for instance, have estimated that during a 180-day journey to Mars astronauts would be exposed to 15 times the radiation limit nuclear power plant workers are subjected to over the course of a year. Astronauts would then suffer further radiation exposure on the planet’s surface, as well as their return journey to Earth.
Perhaps one day, we can protect astronauts from this threat using the secrets we’ve learned from tardigrades. Before genetically modifying the human species, however, there will naturally be any number of ethical and regulatory hurdles that must first be overcome.