Scientists Revive Wheel Animals Frozen For 24,000 Years In Siberian Soil

Scientists Revive Wheel Animals Frozen For 24,000 Years In Siberian Soil

Forbes·2021-06-09 06:14

Photomicrograph of rotifer. Rapidly rotating cilia at top of head, internal organs visible. Live ... [+] specimen. Wet mount, 40X objective, transmitted brightfield illumination. getty Rotifers, also known as wheel animals or wheel animalcules (after of ring of rotating cilia surrounding their mouth and used to feed on algae and microorganisms), are microscopic multicellular animals living in still water bodies (like swamps and ponds). To survive unfavorable conditions, they will enter suspended animation with no measurable metabolism, a condition called cryptobiosis. In cryptobiosis they can survive through drying, starvation, low oxygen levels and temperatures as low as -20°C. When re-hydrated, they will regain their full function in a matter of hours. Past experiments have shown that they can survive about ten years frozen solid, but a new discovery reported in the journal Current Biology pushes the limits of how long they can survive in cryptobiosis far beyond. Russian scientists were able to revive rotifers preserved in 24,000-year-old frozen soil from northeastern Siberia. After thawing some samples coming from 3.5 meters (about 11 feet) beneath ground, the animals started to move, to feed and even reproduce. A genetic analysis has shown that the revived individuals belong to the genus Adineta, a group of rotifers with worldwide distribution, but are a new species. The research team of the Soil Cryology Laboratory at the Institute of Physicochemical and Biological Problems in Soil Science in Pushchino, Russia, tested the survivability of the animals by repeatedly freezing the revived specimens and their modern descendants. The Soil Cryology Lab previously successfully revived single-celled microbes, mosses, plant seeds and a nematode worm found in frozen soil many thousand years old, but the rotifers are the most complex organisms so far to survive being frozen solid. During freezing, ice crystals start to grow inside cells, killing them. Some animals, likely also the rotifers, can produce special molecules to limit the growth and size of ice crystals, surviving the freezing process. "The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to lifea dream of many fiction writers," study author Stas Malavin explains. "Of course, the more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it's not currently possible. Yet, moving from a single-celled organism to an organism with a gut and brain, though microscopic, is a big step forward." The biological mechanisms that allow these organisms to survive could be of interest to better preserve cells and organs of other animals, including humans, for transplantation or research.
……

Read full article on Forbes

Science News