RNA viruses are known for the diseases they cause in humans, from the common cold to Covid-19, and they infect plants and animals important to humans.

These viruses carry their genetic information in RNA instead of DNA, and RNA viruses evolve at much faster rates than DNA viruses, and while scientists have classified hundreds of thousands of DNA viruses in their natural ecosystems, RNA viruses have not been studied.

The discovery resulted in a doubling of the number of known RNA viruses from 5 to 10 (websites).

new search

This is what prompted a group of researchers to try to analyze the genetic material in the ocean, which resulted in the identification of thousands of previously unknown RNA viruses, which doubled the number of reefs or biological groups of viruses that were believed to exist, and team members published the results of their study. New in the journal Science.

The research team consists of a number of researchers in microbiology at Ohio State University, and the researchers explain in their article published on the website "The Conversation" that unlike humans and other organisms made up of cells, viruses lack unique short stretches of "Di". An A" could serve as a genetic barcode without which trying to distinguish between different types of viruses in the wild would be difficult.

To overcome this obstacle, the team decided to identify the gene that codes for a specific protein that allows the virus to replicate its genetic material, because it is the only protein that all RNA viruses have in common, and it plays a key role in how they reproduce. Viruses have slight variations in the gene that codes for a protein that can help differentiate virus types.

There are more RNA viruses in the oceans than researchers previously thought (websites)

So the team examined a global database of RNA sequences from plankton collected during the Tara Oceans expeditions, a 4-year ocean research expedition.

Plankton are any aquatic organisms that are too small to swim upstream, a vital part of ocean food webs and a common host for RNA viruses. The team's examination eventually identified more than 44,000 genes that code for virus proteins.

new viruses

Later, the team used a form of artificial intelligence called machine learning, to systematically organize these sequences and detect differences more objectively compared to performing this task manually, and the team identified a total of 5,504 new marine RNA viruses, which doubled the number of R. NA" is known from 5 to 10 corals.

Mapping these new sequences geographically revealed that two of the new reefs, Taraviricota, named after the Tara expedition, or Arctiviricota - Arctic Ocean viruses - were particularly abundant across vast ocean areas, with regional preferences. Either in temperate or tropical waters.

This map shows the distribution of RNA viruses across the ocean (websites)

The team believes that Taraviricotta may be the missing link in the evolution of the "RNA" viruses that researchers have been searching for for a long time, linking two different known branches of these viruses that differed in how they multiply.

These new sequences will help scientists better understand not only the evolutionary history of RNA viruses, but also the evolution of early life on Earth, as the Covid-19 pandemic has shown that RNA viruses can cause deadly diseases, but they also play a vital role in systems Environmental as it can infect a wide range of organisms, including microbes that affect environments and food webs at the chemical level.

Locating RNA viruses in the world could help explain how they affect organisms that drive many of the environmental processes that run our planet. The study also provides improved tools that could help researchers catalog new viruses as genetic databases grow.

What's Next?

Although many new RNA viruses have been identified, it is still difficult to determine which organisms they infect, and researchers' work is currently limited to portions of incomplete RNA virus genomes, in part due to their genetic complexity and technological limitations.

The team's next step will be to learn what types of genes might be missing and how they have changed over time, and revealing these genes could help scientists better understand how these viruses function.

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