A virus that overturned the conventional wisdom of biology was discovered at the beginning of this century. This virus is called mimivirus and propagates using amoeba, a unicellular eukaryote, as a host.The discovery of the mimivirus, which is larger and more complex than unicellular organisms, has overturned the stereotype that "viruses are small and simple," and researchers around the world have begun giant virus hunting.

　This time, the research team isolated a new giant virus using amoeba as a host from a hot spring pool in a hot spring area in Hokkaido and a mud sample at the bottom of the water, and investigated the details of its infection process, particle structure, and genome composition.As a result, it was found that this new giant virus has many different properties from the previously known giant viruses.

　This giant virus propagates on amoebas as a host, but puts some amoeba cells dormant during the infection process.This property was named "Medusa virus" because it is reminiscent of "Medusa" that turns what you see into stone.In addition, it was revealed that it belongs to a new "family" from its unique particle morphology and genomic composition, such as being the first virus to carry the entire histone gene set.

　In the future, by elucidating the infection process of Medusa virus at the molecular level, it is expected that the co-evolutionary magazine of giant viruses and eukaryotes since ancient times will be unraveled.

Paper information:[Journal of Virology] Medusa virus, a novel large DNA virus discovered from hot spring water