The discovery of ancient viruses unknown to science in the ice of Tibet

In a full-blown pandemic, at a point when a rapid vaccine is trying to contain the spread of new variants of Covid-19, news has been circulating in recent weeks about the discovery of a well. 33 viruses, 28 of which are not yet known to science, were trapped about 15 thousand years ago in the ice of Tibet.. Let’s try to clarify this and understand whether it is appropriate to fear the “discovery” of these ancient viruses by scientists.

There is (almost) no corner of the earth devoid of microorganisms

Let’s start by saying that it is certainly not surprising, from the analysis of ice in remote regions of the planet, that the presence of Microorganisms (In the sense of the term, forgive us the purists, bacteria, yeasts and viruses.) Article describing the discovery of 33 Tibetan viruses – Glacial ice preserves a roughly 15,000-year-old archive of microbes and phagesIt was recently published in the scientific journal microbiome – Certainly not unique. However, if studies aim to determine the presence of bacterial species It has been done for at least a decade, so the literature on this topic is very extensive and recent and less due to the greater complexity of the analysis, Studies dedicated to viruses preserved in ice.

The first reports of microbial presence in glaciers date back to the beginning of the 20th century – He reads the newspaper – But they were largely ignored until the 1980s, when an investigation was conducted into the depths of Lake Vostok. (A subglacial lake found under the Antarctic ice sheet, ed.).“ The results of these studies, published in the late 1990s, revealed Reasonably low concentrations of microorganisms In the deep ice layers (10²-10⁴ cells per ml), much lower than the concentrations found in seawater or soil.

An interesting element is that today these microorganisms are trapped in ice, and they must have existed in ancient times surface deposition, by air, so their knowledge and ability to date their existence (to understand how long they have existed in a nutshell) becomes an important scientific tool for knowing the microbial past of that specific region of Earth. Your study helps with Abstract A Reconstruction of past climatic and environmental conditions “stored” in ice. Important information for scientists to predict future scenarios related to climate change.

Category – Complete the article – On icy islands, proteins, actinomycetes, stability and Bacteroidetes”. In many cases this is possible. bacteria culture Starting with collected samples and somehow awakened from a sleep, if never, very long, due to sub-zero temperatures. It is estimated that some microorganisms live, mainly in the form of sporeAbout 750,000 years deep in the ice.

How hard is it to study viruses!

Bacteria are, as expected, “easy” to analyze by cultural and non-cultural methods, for example, by genetic sequencing. With viruses, things get complicated. Studies conducted in a freezing environment can be calculated at your fingertips. Preliminary research detected the presence of tomato mosaic virus in a 140,000-year-old Greenland ice sample using rt-PCR. Instead, a second search revealed a call. VLPs (Virus-like particles Or particles that look like viruses but do not have a genome) are always found in the depths of Lake Vostok, using transmission microscopy.

It is interesting that recent studies conducted in the Arctic in Cryoconite slots, or we could say about the meltwater trays found on the icy surface, prompting scientists to reassess viral presence in extreme environments. In fact it was determined VLPs concentrations 10^8-10⁹ per gram of sediment. Obviously we’re talking about having viruses on the surface, but as you’d expect for bacteria, since these viruses are now stored in the icy depths, they must be at the surface. How many and who they were is the question that science is trying to answer, pushing boundaries Which has been found so far in the study of “glacial viruses”, which is mainly represented by the limited biomass of the samples, to be the target of metagenomic studies, and the high rate of contamination of the sample with microorganisms on its surface. , which usually occurs when dissolved to undergo microbial studies.

The US team, led by microbiologist and palaeoclimatologist Chi-ping Zhong of Ohio State University, has successfully overcome these obstacles, together. Microsampling cleaning procedures using metagenomic methods in samples with low biomass concentration, to find an answer to the question, with specific reference to the Julia Ice Cap in the western part of the Tibetan Plateau.

Who are the 33 Tibetan viruses?

Let’s immediately answer the question that began at the beginning of this article: No lethal ‘live’ viruses have been reported. The researchers submitted two ice samples for metagenomic analysis, taken respectively on the summit (6710 m) and plateau (6200 m) of the Julia Ice Sheet: one of them dates back to 355 AD and the other to 14400 years ago. They studied the bacterial and viral components.

By focusing on the second, they were able to recognize 33 vOTUs (taxonomic units). In more detail, it was found that 28 Species that science does not yet know And vOTU was not found in any of the 255 veromas compared (a wide range of environments, from deserts to oceans, from arctic to lakes, to creoconite). No wonder this last point, too. We are talking about Viruses have been stored in ice for thousands of years, while the world around them has changed and evolved, and the comparison data set points to current environments.

To particularly highlight the removal of any remaining fear: From genetic comparisons, the researchers concluded that there are viruses stored deep in the Julia Ice Sheet. In the soil or in plants, therefore, not by animal or human transmission. based on Temperamental, and thus viruses that infect bacteria, are thought to have been able to pass on metabolic helper genes to hosts to allow them to Survive more easily in adverse environmental conditions, such as cold and high salinity. Good team play makes us re-evaluate the negative view of viruses in general.

Do you know what is the biggest regret? Now that science – this article is the exposition – is beginning to understand how to study the viruses of the past stored in the depths of glaciers and thus reconstruct their past, it lacks the necessity of such studies: glaciers.

microorganisms in space

Hoping to be faster than climate change in analyzing bacterial and viral communities of the world’s glaciers, scientists are highlighting new protocols for extracting bacterial/viral genomic material from samples collected inn Cold, dry environments at high altitudes, such as the Tibetan Plateau, could pave the way for microbiological analysis of samples from as far away as the Earth, such asPolar satellites of Mars. Or why not, other frozen worlds in our solar system.