Researchers have uncovered thousands of new RNA viruses living in the ocean, Live Science reports.
A team from the Tara Oceans Consortium, which has been studying the microbiome and virome of the world's oceans, analyzed about 28 terabases of RNA sequences they isolated from 35,000 water samples collected at more than 120 sites across the world's oceans. As the team reports in Science, it focuses on RNA viruses by targeting the RdRp gene specific to orthornavirans, finding some 5,000 new RNA viruses. The team additionally examined divergence in the RdRp gene to build a phylogenetic tree.
This analysis doubled the number of orthornaviran phyla from five to 10, dubbing the new phyla Arctiviricota, Pomiviricota, Paraxenoviricota, Taraviricota, and Wamoviricota.
With a global phylogenetic tree, senior author Matthew Sullivan from Ohio State University tells The Scientist that researchers can also examine the early stages of RNA viral evolution. "RdRp is supposed to be one of the most ancient genes — it existed before there was a need for DNA," first author Ahmed Zayed from Ohio State says in a statement. "So we're not just tracing the origins of viruses, but also tracing the origins of life."