In brief Researchers studied single-celled algae, called diatoms, from the Arctic that were previously assumed to be hibernating in the ice and found they were actually quite active.
This activity, which continued when temperatures dropped to -15 C, is the coldest-ever movement recorded for a eukaryotic cell.
The diatoms move through a type of gliding, which is enabled by a combination of mucus and molecular motors that are similar to systems seen in human muscles.
Given how abundant these diatoms are in the ice, understanding their activity could tell us more about the ecology of the Arctic, including new information about the food chain and ice formation.
If you pull an ice core from the outer edges of the Arctic polar cap, you might spot what looks like a faint line of dirt. Those are diatoms – single-celled algae with outer walls made of glass. Their presence in ice isn’t new, but because they seemed trapped and dormant, few bothered to study them.
But new research from Stanford, published Sept. 9 in Proceedings of the National Academy of Sciences, revealed Arctic diatoms aren’t immobile or entombed. They’re not just surviving either – they’re gliding into the record books.
“This is not 1980s-movie cryobiology. The diatoms are as active as we can imagine until temperatures drop all the way down to -15 C, which is super surprising,” said Manu Prakash, associate professor of bioengineering in the Schools of Engineering and Medicine and senior author of the paper.
That temperature (5 F) is the lowest ever recorded for movement by a eukaryotic cell – the type of complex cells in plants, animals, fungi, and more, defined by having a nucleus inside a membrane.
“You can see the diatoms actually gliding, like they are skating on the ice,” said lead author and Stanford postdoctoral scholar Qing Zhang, who collected the samples during an Arctic research expedition. She and her colleagues demonstrated not only motility at such low temperatures, but also that their gliding – or skating – relies on a combination of mucus and molecular motors.
Navigating a bustling ’berg
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