Scientists revive tardigrades frozen for more than 30 years

It's already been established that they can survive deep in the ocean and in outer space.And according to new research from Japan, tardigrades also known as water bears can even survive beingfrozen solid for decades on end.

CBC Radio science columnist Torah Kachur explains what this means forthe so-called "toughest creature on the planet."

What makes 'water bears' so remarkable?

Water bears, tardigrades,moss piglets whatever you call them, these tiny microanimals(usually small enough to fit on the head of a pin) canlive pretty much everywhere. Their favourite spot is onmoss, which they feed on. I found one swimming in a sample of pond water that I was exploring in a microscope and I have to say, they're almost cute,withthick bodies, eight tiny legs, and a sucker-style mouth.

You've also probably eaten them. They like to live onlettuce or spinach, and without rigorous scrubbing, you've likely had a water bear for lunch.

But what makes them truly amazing is their survivability. They've been experimented on in space, and found in a huge range of environments on Earth, from tropical rainforests to Antarctica to the deep sea. They can survive extreme heat, extreme cold, and extreme pressure.

What does this latestresearch tell us about their ability to survive?

It's been previously established that tardigrades can survive being frozen but now we know they can survive being frozen for an incredibly long time.

Japanese researchers successfully thawed some water bears frommoss frozen in Antarctica in 1983 which means they survived being frozen for more than 30 years.

How do you reanimate something frozen in ice for 30 years?

Slowly.

The researchersthawed a moss sample that had been gathered in Antarctica in 1983, and stored at a temperature of -20 C. The sample was thawed at 3 C for 24 hours, and then placed in a Petri dish withfresh water.

Two adult water bears survived the thawingalthough it took about nine days until they were fully functional. So didseveral eggs which weresuccessfully hatched.

Remarkably, one of the adults and one of the water bears hatched from a frozen eggwereable to reproduce successfully,which means there wasno significant damage to its DNA in that long freezing period, which would have made it infertile.

What are the broader applications for scientists?

Hopefully a lot. The resistance of tardigrades to all sorts of environmental extremes means they have some biological secrets, andtheir DNA must be particularly resistant to damage.

One of the main things that happens when we ageor when we get cancer, for exampleis that our DNA gets damaged. That, in turn, affects our cells and organs. We have a capacity to repair damage done to our DNA, but possibly not as effectively as some organisms like the water bear.

So they may be able togive us clues as to how we can harness the power of our own genomes to do the same.

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