Tiny organism reproduces after spending more than 24,000 years frozen

Adineta sp. isolated from permafrost, site of sampling, results of bioinformatics and experimental procedures. (A), (B), and (C) taken on a Canon Eos 600-D APS-C camera under a modified Reichert Diastar microscope with Zeiss planapo DIC optics and custom-built flash. Images were post-processed in Adobe Photoshop ® for contrast and color balance. (Credit: Lyubov Shmakova, Stas Malavin, Nataliia Iakovenko, Daniel Shain, Michael Plewka, Elizaveta Rivkina)

TORONTO -

A microscopic organism survived 24,000 years in Siberian permafrost and lived to reproduce, according to a Russian study.

Bdelloid rotifers are known for their ability to survive, particularly in unwelcoming environments like extreme cold. They are typically found in freshwater habitats all around the world.

The tiny multicellular animals were found when researchers collected samples 3.5 metres below the ground surface of Siberian permafrost.

Once thawed, the rotifers were able to reproduce, despite being frozen for millennia. The tough little animals are an entirely female species that reproduce asexually.

Cryo-freezing has been the focus of much science fiction. Now these tiny rotifers could shed some light on the process. Prior to this research it was thought that bdelloid rotifers could survive up to 10 years when frozen.

"The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to life -- a dream of many fiction writers," Stas Malavin, co-author and scientist at the Soil Cryology Laboratory at the Institute of Physicochemical and Biological Problems in Soil Science, said in a press release.

To better understand the process, researchers froze and thawed rotifers and found that they were able to remain undamaged from ice crystals that form during slow freezing, suggesting some sort of mechanism to protect their organs and cells from damage caused by extremely low temperatures, according to the release.

While cryo-freezing may not yet be a possibility for humans and other mammals, it’s a step in the right direction.

“Of course, the more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it's not currently possible,” said Malavin. “Yet, moving from a single-celled organism to an organism with a gut and brain, though microscopic, is a big step forward."