The story of nematodes waking up from the freeze after 46,000 years

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Many witnesses who experienced the events of Mihitala Purana have now perished. But some are stony, staring at the endless march of time. Examples include the ancient ice sheets of Siberia and the glaciers at the North and South Poles that are being battered by rising global temperatures. They still harbor prehistoric microbes and germs that lay dormant for millions of years before the advent of man. That is why a sane person would not drink the water that melts from a glacier and thinks it is pure.

Emphasizing this even more, last year scientists were able to identify a number of deadly pathogenic bacteria that were dormant in the frozen Lake Hazen located north of the Arctic Circle. Ten months later, on July 27, a study was published in the journal PLOS Genetics that reactivated a nematode worm that had spent 46,000 years dormant under the snow.

This new species of nematode (in terms of sequence found) was discovered in 2018 in a drill 130 feet below the surface of permafrost in Siberia. They are scientifically known as Panagrolaimus kolymaensis. After undergoing radiocarbon dating of the plant material in the excavated soil layer, it has been found to be 46,000 years old.

‘Radiocarbon dating is certainly accurate. We now know they have been around for 46,000 years,’ said Teymuras Kurchalia, a cell biologist at the Max Planck Institute for Molecular Cell Biology and Genetic Technology and a co-author of the study.

Researchers note that its age may vary by only a thousand years. The idea is that this microscopic worm has been hibernating since the Pleistocene. The average lifespan of a nematode of this species is two months! That is, if the freezing process was not reached, its death would have happened 46,000 years ago.

It’s amazing how it was preserved for so long. This single being; The first worm they found was alive from such a long time ago,’ said Gregory Copenhaver, director of the University of North Carolina’s Department of Evolutionary Sciences, expressing his surprise at this unique event.

As scientists have recognized for a long time, certain microscopic organisms voluntarily stop the flow of their life under harsh environmental conditions. It is by immersing oneself in a subtle slumber to the extent that the function of one’s body cannot be grasped externally. This process is scientifically called cryptobiosis or half life. The nematodes found in the soil samples from Siberia also passed this stage.

Scientist Philip Schiffer of the Department of Zoology at the University of Cologne in Germany, who led the research, says that bringing the worm back to an active state depended on an extremely simple process. What they had done was to dissolve the rocky soil. They had been careful to provide heat so that the nematodes inside would not be scalded and destroyed. The nematodes were then observed squirming, indicating that they had reactivated. The researchers then allowed them to grow in a lab dish. They had also begun breeding the species by growing and reproducing on the bacteria provided as food.

The first nematode to be studied is now dead. But researchers have been able to successfully harden about 100 other generations descended from that nematode.

Nematodes reproduce according to the process of asexual reproduction called parthenogenesis. During this study, the researchers were more curious not about how the nematodes survived for so long, but how they entered their dormant state.

The researchers found out from the experiments carried out using the offspring born later
The C. elegans nematode species is able to survive freezing and wakes up in warm environmental conditions before freezing. During this freezing stage, trehalose, a sugary liquid, is released from their bodies. Its purpose is to prevent their DNA, cells and proteins from decomposing during the freezing period.

Professor Teymuras Kurzchalia of the Planck Institute for Molecular Cell Biology and Genetics, a co-author of this study, points out that discovering what proteins are released during this freezing process will be helpful for the improvement of medicine. Research is already underway for that.

Another question researchers are eager to answer is whether time is a limiting factor in reawakening from hibernation. Among the thousand and one questions that need to be answered in the future is what will be the role of evolution and extinction in a setting where species that are born, die, and die in the span of a few weeks extend their life span by centuries or millennia. have joined

However, some scientists outside the academic process point out that some parts of this cannot be accepted. Biologist Byron Adams is one such. ‘I would also like to believe that the animals they describe have been surviving on rocks for 40,000 years. If I am a betting man, I will take even a bet that such a thing can actually happen,’ he says.

But he points out that in the study, only the plant parts of the respective soil layers have been used to measure the age. There is also a possibility that the actual age of the nematodes may not be represented. As he further points out, it is also possible that the soil sample was exposed to modern nematodes that remained in the surface soil while taking it up from the ground. In 2018, when this soil sample was obtained, there were arguments about this.

To clear this doubt, Adams suggests that some surface samples should be taken from around the area and the nematodes present in them should be studied. This doubt will disappear if the nematode species found under the permafrost layer are not among the nematode species.

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