Over 5,500 new RNA viruses found in the ocean, including a missing link in viral evolution

Amazing stuff! What little we still know about our oceans!

Lot's of potential for zoonotic or other transmission!

"An analysis of the genetic material in the ocean has identified thousands of previously unknown RNA viruses and doubled the number of phyla [from 5 to 10], or biological groups, of viruses thought to exist ...

RNA viruses are best known for the diseases they cause in people, ranging from the common cold to COVID-19. They also infect plants and animals important to people. ...

RNA viruses evolve at much quicker rates than DNA viruses do. While scientists have cataloged hundreds of thousands of DNA viruses in their natural ecosystems, RNA viruses have been relatively unstudied. ...
we decided to identify the gene that codes for a particular protein that allows a virus to replicate its genetic material. It is the only protein that all RNA viruses share, because it plays an essential role in how they propagate themselves. Each RNA virus, however, has small differences in the gene that codes for the protein that can help distinguish one type of virus from another. ...
Plankton are ... common hosts for RNA viruses. ..."

"... These viruses require an ancient enzyme, RNA-directed RNA polymerase (RdRp) for replication, which is thus used as a marker of deep evolutionary relationships. ..."

From the abstract:

"... RNA viruses are insufficiently studied outside disease settings. In this study, we analyzed ≈28 terabases of Global Ocean RNA sequences to expand Earth’s RNA virus catalogs and their taxonomy, investigate their evolutionary origins, and assess their marine biogeography from pole to pole. Using new approaches to optimize discovery and classification, we identified RNA viruses that necessitate substantive revisions of taxonomy (doubling phyla and adding >50% new classes) and evolutionary understanding. “Species”-rank abundance determination revealed that viruses of the new phyla “Taraviricota,” a missing link in early RNA virus evolution, and “Arctiviricota” are widespread and dominant in the oceans. These efforts provide foundational knowledge critical to integrating RNA viruses into ecological and epidemiological models."

Over 5,500 new viruses found in the ocean, including a missing link in viral evolution

Cryptic and abundant marine viruses at the evolutionary origins of Earth’s RNA virome