Stowaways in the Genome: Thousands of Unknown Viruses Hide in the DNA of Unicellular Organisms
Published:16 Apr.2023    Source:University of Innsbruck

During a large-scale study of complex single-celled microbes, researchers from the University of Innsbruck made an unexpected discovery. Built into the genome of the microbes, they found the DNA of over 30,000 previously unknown viruses. This hidden DNA may allow the replication of complete and functional viruses in the host cell.


These viruses do not appear to harm their hosts. On the contrary, some may even protect them. Many appear to be similar to so-called virophages. These viruses infect and destroy other, harmful viruses that infect their host cell.The DNA of the newly discovered viruses is similar to virophage DNA. Therefore, it is probable that the host microbes protect themselves from giant viruses through these built-in viruses.


The research project was originally based on a new group of viruses that Bellas and Sommaruga discovered in the water of the Gossenköllesee in Tyrol, Austria, in 2021.With the high-performance computer cluster "Leo" of the University of Innsbruck and the new Oxford Nanopore technology, the researchers found much more than the viruses they were looking for, which will inspire more research to study the roles that these viruses play.