New research based on an expedition to the icy waters of Greenland reveals rising levels of antifreeze proteins in a small snail species, underlying the importance of this unique adaptation to life in sub-zero temperatures. The study, led by scientists from the American Museum of Natural History and the City University of New York (CUNY), and published today in the journal evolutionary bioinformaticsIt also warns that warming ocean temperatures in the Arctic could pose a threat to these highly specialized fish.
David Gruber said, “In the same way that the antifreeze in your car prevents the water in your radiator from freezing in cold temperatures, some animals have evolved amazing machinery that protects them from freezing, such as antifreeze proteins, which allow ice crystals to form. stop it.” Research Associate at the Museum and a Distinguished Biology Professor at CUNY’s Baruch College. “We already knew that this tiny snail, which lives in extremely cold water, produced antifreeze proteins, but we didn’t know how loaded it is with those proteins – and how much it takes to make these proteins. was trying .”
The icy waters of the polar oceans are an extreme environment for marine life, limiting residents with mechanisms to cope with freezing temperatures. Unlike some species of reptiles and insects, fish cannot survive the partial freezing of their body fluids, so they are primarily used to prevent the formation of large ice grains inside their cells and body fluids. Antifreezes made in the liver depend on proteins. The ability of fish to make these special proteins was discovered about 50 years ago, and scientists have since determined that antifreeze proteins are made up of five different gene families.
Gruber and co-author John Sparks, a curator in the museum’s Department of Ichthyology, decided to investigate the antifreeze protein of the juvenile variety snail, lipiris gibbousAfter encountering a different extraordinary ability of biofluorescence – small fish. In 2019, as part of Constantine. S. Niarchos Expedition, Sparks and Gruber were exploring iceberg habitats off the coast of eastern Greenland when they found a juvenile variety of snail that glows green and red. Biofluorescence, the ability to convert blue light to green, red or yellow light, is rare in Arctic fishes – where there is prolonged darkness – and the snailfish is the only polar fish known to have biofluorescence.
Upon further examining the snail’s biofluorescent properties, the researchers found two distinct types of gene families encoding for antifreeze proteins. The snail genes have the highest expression levels of antifreeze proteins ever observed, highlighting their importance for the survival of these animals and sending a red flag about how they might fare in warming environmental conditions.
“Since the mid-20th century, temperatures in the Arctic have risen twice as fast as in the middle latitudes, and some studies predict that if Arctic sea ice decline continues at this current rate, the Arctic Ocean will be mostly ice-free in the summer. within the next three decades,” Sparks said. “Arctic seas do not support a high diversity of fish species, and our study predicts that with increasingly warming ocean temperatures, ice-dwelling specialists such as this snail may face increased competition by more temperate species that previously These were unable to survive in the high northern latitudes.”
Other authors on this study include John Burns, of the American Museum of Natural History and the Bigelow Laboratory for Ocean Science; Jean Gaffney, CUNY; and Mercer Bruegler, American Museum of Natural History and University of South Carolina Beaufort.
This research was supported by AMNH Constantine S. The Niarchos Campaign was generously supported by the Stavros Niarchos Foundation through a grant.
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