Mirusviruses, New Ocean Viruses Discovered – Editorial

By exploring data from the Tara Ocean Foundation expeditions, scientists have discovered a new type of virus: viruviruses. This discovery could make it possible to understand the source of herpes and better understand the biodiversity of the oceans.

Ocean alien viruses circulate in abundance. Possible relatives of the herpes virus have been discovered thanks to data collected by an expedition from the scientific schooner Tara Ocean, according to a study published Wednesday, April 19. viruses are called viruses (“Miros” Means “strange” In Latin), these DNA viruses are ubiquitous on the surface of the seas and oceans, from the equator to the poles, where they infect plankton. “These are chimeric viruses, midway between giant viruses, which are also abundant in the oceans where they only infect single-celled organisms, and herpesvirus, which only infects animals whose humans it infects.”describes biologist Tom Delmont, CNRS researcher and author The study was published in nature.

The unexpected discovery was made at Genoscope in Evry (Essonne), where the genomes collected by the Tara Océan Foundation are sequenced. “We were exploring data tsunami From the 2009-2013 expedition, with 300 billion DNA sequences, when we came across an unusual evolutionary signal”says the microbial ecologist. Signal for a specific gene carried by giant viruses, as well as mirusviruses. “It was like finding treasure on a huge sandy beach with a metal detector”The researcher continues. After several years of analysis, scientists from the Tara Ocean Consortium and their collaborators have been able to describe this new group of highly complex and diverse viruses.

A natural and helpful presence

This discovery will allow for a better understanding of ocean biodiversity and the importance of viruses in these ecosystems. “We only see viruses as diseases, but their presence in the oceans is natural and beneficial – just like our gut microbiota.”According to Tom Delmont. “By infecting the cells, it destroys them and this returns nutrients to the ecosystem. This allows the plankton to regenerate.develops the world of biology.

These viruses also have a fascinating evolutionary history because the particular structure of their genome suggests that they do “distant cousins” herpes. Herpes viruses circulate in animals and infect more than half of the world’s population. But it is completely absent from single-celled marine organisms. “The puzzle can be explained as follows: thanks to mirusviruses, we imagine what the oceanic progenitor of herpes might have been. This progenitor would have infected single-celled organisms in the oceans millions of years ago, before it specialized in infecting animals.Tom Delmont explains.