An international team of researchers in Brazil has identified an enigmatic virus whose genome seems to be almost entirely new to science. Last month, the researchers published a paper on the preprint server bioRxiv detailing their analysis of the new virus. The so-called Yaravirus is named after Yara – or Iara, a water-queen figure in Brazilian mythology. It was recovered from Lake Pampulha, an artificial lake in the Brazilian city of Belo Horizonte.
Two of the senior members of that team were virologists – Bernard La Scola from Aix-Marseille University in France, and Jônatas S. Abrahão from Brazil’s Federal University of Minas Gerais. Prior to their discovery, it was thought that viruses couldn’t do things the new specimen exhibited. They were regarded as inert, non-living entities, only capable of infecting their hosts. In their investigations, the researchers found that over 90 per cent of the Yaravirus genes had never been described before. They are typically known as orphan genes (aka ORFans).
The team found the Yaravirus in Lake Pampulha in Belo Horizonte and sequenced its genome. They discovered that only six of its genes even slightly resembled viral genes previously recorded in public database. The rest of the eight genes were completely new. The discovery of an almost wholly unique virus might seem particularly worrisome but scientists regularly discover new viruses. Between 2016 and 2019, the number of distinct types of viruses scientists knew about in the world’s oceans surged from 15,222 to 195,728.
The importance of Yaravirus’s discovery lies mostly in the fact that it expands the wealth of human knowledge. The tiny infectious agents play a major role in the health of Earth’s entire ecosystem — for better and for worse. Either way, it’s clear we still have an awful lot to learn, the researchers say.