A new family of ‘mirusviruses’ has been discovered in the oceans

A new family of viruses called “Mirusvirus” (“mirus” means “strange” in Latin), distant neighbors of the herpesvirus, has been revealed by the Tara Ocean Foundation. This was revealed by a study published on April 19, 2023 in the Scientific Journal nature. The Tara Ocean Foundation collected data between 2009 and 2013 during various expeditions and sequenced genomes collected from the surface of the seas and oceans in Genoscope of the Evry Genopole.

A family of viruses halfway between herpes virus and giant viruses

DNA viruses, halfway between giant viruses and herpes virus, existed from the equator to the poles. “These viruses have an amazing evolutionary history, halfway between the herpes virus, which affects half of the world’s population, and giant viruses, which are an entirely separate group of viruses found abundantly in the oceans.”He specifies CNRS press release about discovery.

before adding: “Herpes viruses are common in animals (half of the world’s population is infected with the herpes virus), but they are completely absent from the rest of life, leaving the question of their evolutionary origin unanswered.”

The results of this study support the hypothesis that ancestors of herpesviruses could infect marine single-celled organisms in the past. In 2018, our research team noticed an unusual evolutionary signal in the tsunami sequence data from the Tara Oceans. Monitoring this signal allowed us to detect and subsequently characterize a major group of DNA viruses: mirusviruses.”CNRS continues.

This discovery disrupts the understanding of plankton ecology

“Mirusvirus is the complement of the ocean that infects planktonic herpes, which infects humans. So even if you drink a cup, you can drink a little, but there is no danger”Tom Delmonte, a CNRS researcher who specializes in microbial ecology, explains, interrogated by franceinfo.

According to the researcher, these viruses will be involved in regulating ocean plankton, organisms essential for the survival of our ecosystems: “It will infect the cells. The cell will die, and it will release a lot of nutrients that will be reused by the rest of the community and allow the community to regenerate and rejuvenate.”

“Tara Ocean has transformed our understanding of plankton ecology. This incredible expedition also allows us to answer fundamental questions of evolution. There is still much to discover and understand about viroid viruses. There is no known culture, we have no picture of their virus particles, and we have not yet begun to study them.” anywhere other than the oceans.”Morgan Jaya, a microbiologist at the National Sequencing Center and first author of the study.

The oceans, an ecosystem that is still very well known

“The oceans are still an ecosystem that we know fairly poorly in generalThe expert continues. This is especially true for viruses that have been focused on for decades rather than antivirus methods. And finally, for 20.30 years, we recognize that it is particularly important from this point of view.

Now the scientists’ goal is to grow these viruses to learn more about ocean biodiversity.