Tardigrades, also known as waterbears or moss piglets, are tiny water-dwelling organisms. They’re segmented, with eight legs, measure 1mm in length – and are one of the toughest creatures on the planet.
Found throughout the world, tardigrades can survive extreme pressure, such as deep underwater, and can even live in the vacuum of space for several days.
When they’re frozen, the creatures enter a state called cryptobiosis, in which their metabolic processes shut down, and they show no visible signs of life.
It’s a similar story when they’re dried out – after being completely desiccated, they can remain in a dehydrated state for up to a decade before being revived. How they do this has been a mystery for more than 250 years.
Now, scientists believe they have found out how tardigrades survive desiccation. According to a new study published in the journal Molecular Cell, the creatures have unique genes that create tardigrade-specific intrinsically disordered proteins (TDPs).
It is these TDPs that preserve desiccated water bears: when hydrated they have jelly-like structure, which becomes more like glass without water.
Research lead Dr Thomas Boothby said: "The big takeaway from our study is that tardigrades have evolved unique genes that allow them to survive drying out.
"In addition, the proteins that these genes encode can be used to protect other biological material – like bacteria, yeast, and certain enzymes – from desiccation."
Early last year it emerged that researchers has successfully revived tardigrades that had been kept frozen for 30 years.
Scientists at at Japan’s National Institute of Polar Research retrieved the creatures from a frozen moss sample collected in Antarctica in 1983. The sample had been stored at −20 °C for just over three decades.