The toughest animals in the world’s secrets are told

It is well known that tardigrades, which are sometimes called “water bears,” are some of the toughest animals in the world. These tiny beings, which are less than a millimetre across, are amazingly strong. They can survive cosmic disasters, radiation, freezing temperatures, great dehydration, and even the vacuum of space. Now, a new genetic study has revealed some of the mysteries behind their amazing ability to stay alive.

The study, which was published in the journal PLOS Biology, looks at the DNA of two types of tardigrade to find the genes that help them recover from desiccation, a process in which they lose all of their water.

Usually, you can find tardigrades in places that dry out quickly, like grass and ponds. They have evolved over time to be able to survive being completely dry and then come back to life when they come into contact with water years later. Their genes are what will help them stay alive, as this study shows. When it is dry, certain genes in tardigrades make proteins that fill in the water that is missing in their cells. When water is available again, these proteins break down, letting the cells fill up again.

When we understand this natural way that tardigrades stay alive, it has effects that go beyond these tough animals. Professor Mark Blaxter, a co-author from the University of Edinburgh, talks about the possible benefits for people. He imagines uses like sending live vaccines around the world without having to keep them cold.

Professor Blaxter says, “Tardigrades’ amazing skills can help us find new ways to solve problems in the real world, like how to transport vaccines.”

A long-running debate about the genetic history of tardigrades is also looked at in the study. Their unique look—eight short legs and claws—may make it seem like they are related to insects and spiders. Genetic tests, on the other hand, show an unexpected change. The researchers figured out how the HOX genes work. These genes control how the embryo’s head and tail grow and where its limbs go. While most species have ten HOX genes, tardigrades only have five. Some roundworms are the same way.

Professor Blaxter says, “This was a real surprise that we weren’t expecting.” The results go against what people thought they knew and show that tardigrades and worms have a stronger genetic link than insects.

Additionally, the genetic research found a group of proteins that protect tardigrade DNA, which may explain why they can survive radiation.

“These cute little animals have interested me for twenty years.” Prof. Blaxter says, “It is great to finally have their complete genomes and to start to understand them.” The results of this study not only make us appreciate tardigrades’ strength even more, but they also open up new areas for science research and possible uses in helping people with their problems.