2023-08-16 15:28:00
Since their discovery in Siberia, these small worms have been the subject of numerous publications and scientific research. Point.
This is a discovery that has been talked about for many years. And for good reason, these little worms found frozen in the permafrost in Siberia are surprising. We explain to you why and above all what issues surround their “return to life”.
Discovered in 2002 and resurrected in 2018
A strange little microscopic roundworm was discovered by scientists during an expedition to study permafrost in Siberia near the Kolyma River in the Arctic in 2002. The specimens trapped in the ice of a burrow of fossilized squirrel were frozen. They were repatriated to Moscow in order to be studied.
These nematodes were called Panagrolaimus kolymaensis in reference to the name of the river.
The researchers managed to “resurrect” which earned a publication in 2018 in the scientific journal Doklady Biological Sciences.
They were thus able to awaken from their sleep by being thawed in Petri dishes with agar-agar and E. coli bacteria to feed them. The worms have since reproduced on a hundred generations in a few years.
Dating
Initially, researchers thought the worms had remained frozen for 30,000 to 40,000 years. But after studying these specimens for years, scientists from the Institute of Zoology at the University of Cologne and the Max Planck Institute for Molecular Cell Biology and Genetics in Dresden, Germany discovered from their food bolus that the dating was much older: between 45,839 and 47,769 years old.
New species DNA
Moreover, in the conclusion of their work published in the journal Plos Genetics a few days ago, the researchers estimate with the study of its DNA that this worm belongs to a new species which until then had never been identified.
How could they survive? What is cryptobiosis?
Cryptobiosis is the state of slowed down life thanks to which certain living species can resist unusual living conditions, sometimes for very long periods of time.
Simply put, metabolism is paused to deal with extreme conditions and organisms go dormant – much like hibernation. Thanks to this mechanism, the worms can survive without water or oxygen, under extreme temperatures, very high or very low. And they get there through a sugar, trehalosewhich protects them.
The most resistant species known
Some examples of cryptobiosis had already been identified in the past. A spore of the Bacillus bacteria found in theabdomen of bees encased in amber for 25-40 million years or even a lotus seed over 1,000 years old to 1,500 years old found in a lake that may have germinated.
Examples of metazoans such as tardigrades, rotifers and nematodes in cryptobiosis are legion, but so far it had not exceeded 40 years: the lectus murrayi with 25.5 years in frozen foam at -20°C and Tylenchus polyhypnus with 39 year old desiccated in a herbarium specimen.
The study of the ability to enter into cryptobiosis could be interesting for research.
Bacteria and viruses locked in ice could thus “wake up” and spread
The question arises in the fact that with global warming, bacteria and viruses locked up and frozen in the ice could resurrect.
With 968 species of micro-organisms that have been discovered trapped in the ice in Tibet, or even a “zombie virus” reactivated after spending 48,500 years in the Siberian ice, the risk is not insignificant.
If they were reactivated naturally, they could indeed be a threat to public health.
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