Researchers Discover Arctic Algae with Unique Ability to Traverse Ice at Extremely Low Temperatures (-15°C)
In the frigid expanse of the Arctic, scientists have made a groundbreaking discovery: single-celled algae called diatoms are moving within the ice. This revelation, made during a 45-day summer expedition through the Chukchi Sea, has opened up a new world of understanding about the Arctic ecosystem.
During their research, the team collected ice cores from 12 locations. Upon examination, they found diatoms gliding in narrow, hair-thin channels. These diatoms were primarily from the genus Navicula, as identified using microscopy and DNA barcoding.
The movement of these Arctic diatoms may be influenced by light and salt availability in the Arctic environment. Remarkably, these microorganisms are capable of moving through actual ice, unlike their temperate counterparts.
Arctic diatoms exhibit a unique adhesion to ice surfaces, a phenomenon believed to involve specialized ice-binding proteins. The diatoms' movement is facilitated by a protein-rich secretion called mucilage, which contains the same molecular machines that power human muscles: actin and myosin.
This discovery could potentially influence ice formation and melting. Researchers are focusing on the slime filament mechanism involving actin and myosin to understand how these biological systems function at temperatures as low as -15 °C.
The researchers also built a thermodynamic model that simulates the balance of internal forces and external drags in Arctic diatoms. They discovered that Arctic diatoms have evolved lower internal energy demands and external materials that change less with temperature than those of temperate species.
This evolutionary advantage allows Arctic diatoms to move nearly ten times faster on ice at freezing temperatures compared to their relatives in temperate climate zones.
The Arctic ecosystems, including the diatom-based food chain, could be at risk due to budget cuts for polar research and the potential loss of infrastructure like the Sikuliaq. Without support for tools like Zhang's sub-zero microscope, entire microbial worlds could remain uncharted.
Arctic diatoms are super important in the polar food web, forming the base of an ecosystem that sustains various species, including krill, seals, and polar bears. This discovery not only deepens our understanding of the Arctic but also highlights the importance of continued research in this critical region.
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