Beneath the Arctic’s frozen floor, tiny algae are defying the foundations of biology.
Their survival technique not solely redefines the bounds of life but additionally raises pressing questions on ecosystems disappearing with the melting Arctic.
Dormant No Extra: Arctic Diatoms Come Alive
Should you drill into the sides of the Arctic polar cap and pull up an ice core, you might discover what appears to be like like a skinny streak of dust. In actuality, these faint strains are made up of diatoms, single-celled algae encased in glass-like shells. Scientists have recognized they had been current in ice for a while, however as a result of they appeared frozen and inactive, they had been largely neglected.
That assumption has now been overturned. A research from Stanford, printed September 9 in Proceedings of the Nationwide Academy of Sciences, exhibits that Arctic diatoms are removed from immobile. In truth, they don’t seem to be merely enduring the chilly, they’re actively shifting by it, incomes a spot within the scientific report.
Report-Breaking Survival in Excessive Chilly
“This isn’t Nineteen Eighties-movie cryobiology. The diatoms are as lively as we will think about till temperatures drop all the way in which all the way down to -15 °C, which is tremendous shocking,” stated Manu Prakash, affiliate professor of bioengineering within the Faculties of Engineering and Medication and senior creator of the paper.
That determine, equal to five °F, is the bottom temperature ever documented for motion in a eukaryotic cell, the kind of complicated cell present in crops, animals, fungi, and different organisms, all of that are outlined by a nucleus surrounded by a membrane.
“You possibly can see the diatoms really gliding, like they’re skating on the ice,” stated lead creator and Stanford postdoctoral scholar Qing Zhang, who collected the samples throughout an Arctic analysis expedition. She and her colleagues demonstrated not solely motility at such low temperatures, but additionally that their gliding – or skating – depends on a mix of mucus and molecular motors.
Contained in the Arctic Expedition
The diatoms featured on this analysis resulted from a 45-day Arctic expedition within the Chukchi Sea aboard the analysis vessel Sikuliaq, which is owned by the Nationwide Science Basis and operated by the College of Alaska Fairbanks. Researchers from the Prakash Lab and the lab of Kevin Arrigo, professor of Earth system science within the Stanford Doerr Faculty of Sustainability, collected ice cores from 12 stations all through the summer time of 2023. Utilizing a variety of on-ship microscopes that the Prakash Lab has been creating for years, the staff was in a position to picture inside ice and doc the key lives of those unimaginable arctic diatoms.
Again within the lab, the staff extracted diatoms from the ice cores and recreated their environments in a petri dish containing a skinny layer of frozen freshwater and a layer of very chilly saltwater. When ice types within the Arctic, it kicks out salt, leaving freshwater ice with small microfluidic channels in it – so the lab additionally made channels of their ice, utilizing their very own hair.
Whilst they lowered the temperatures of a particular sub-zero microscope under freezing, the diatoms slipped by the strand-sized highways. Additional experiments, utilizing gels seeded with fluorescent beads, tracked their actions like footprints in sand.
The Secret of Mucus-Powered Movement
What’s so shocking is that the diatoms cruised alongside with out wiggling, scrunching, or utilizing any appendages. As an alternative, they observe the artwork that many diatoms show: gliding.
“There’s a polymer, form of like snail mucus, that they secrete that adheres to the floor, like a rope with an anchor,” stated Zhang. “After which they pull on that ‘rope’ and that offers them the drive to maneuver ahead.”
The mucilage rope mechanism will depend on actin and myosin – the identical organic system that drives human muscle actions. How that equipment nonetheless works in subzero situations is now a key analysis query the lab is pursuing. When the staff in contrast Arctic diatoms with temperate relations gliding alongside glass, the polar species moved much faster, hinting at an evolutionary advantage.
Beneath the Ice: A Hidden Green World
The Prakash Lab made the most of their time in the Arctic and gathered an abundance of data on multiple projects, in addition to diatoms. That includes drone footage, taken under the ice, that vividly displays the potential of this work.
“The Arctic is white on top but underneath, it’s green – absolute pitch green because of the presence of algae,” said Prakash. “In some sense, it makes you realize this is not just a tiny little thing, this is a significant portion of the food chain and controls what’s happening under ice.”
Urgency in a Disappearing Arctic
Knowing the diatoms are active raises broader questions about adaptation to a changing polar environment. Could they be moving resources through the Arctic food web, nourishing everything from fish to polar bears? Could their mucus trails even seed new ice formation, the way pearls form around grains of sand?
Normally, Prakash wouldn’t show his hand when it comes to these kinds of nascent ideas, but the stakes this time are different, he said.
“Many of my colleagues are telling me, in the next 25 to 30 years, there will be no Arctic. When ecosystems are lost, we lose knowledge about entire branches in our tree of life,” he said, noting that severe projected budget cuts to the National Science Foundation are predicted to reduce polar research funding by 70 percent. “I feel a sense of urgency in many of these systems, because, at the end of the day, the infrastructure and capacity to be able to operate is critical for discovery.”
Reference: “Ice gliding diatoms establish record-low temperature limits for motility in a eukaryotic cell” by Qing Zhang, Hope T. Leng, Hongquan Li, Kevin R. Arrigo and Manu Prakash, 9 September 2025, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2423725122
Prakash is also a senior fellow at the Stanford Woods Institute for the Environment, associate professor, by courtesy, of biology and of oceans, a member of Stanford Bio-X, the Wu Tsai Human Performance Alliance, the Maternal & Child Health Research Institute, and the Wu Tsai Neurosciences Institute. Other authors include graduate student Hope T. Leng, Hongquan Li, PhD ’23, and Kevin Arrigo. Arrigo is the Donald and Donald M. Steel Professor of Earth Sciences, a senior fellow at the Stanford Woods Institute for the Environment, and a member of Bio-X.
This research was funded by the National Science Foundation, a Stanford VPGE DARE fellowship, the Human Frontier Science Program, the Moore Foundation, the Schmidt Foundation, and the Dalio Foundation. Part of this work was performed at the Cell Sciences Imaging Facility at Stanford University.
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