What is "mycovirus"

n. Any virus that infects fungus.

Mycoviruses (ancient Greek μύκης mykes: fungus and Latin virus) are viruses that infect fungi. The majority of mycoviruses have double-stranded RNA (dsRNA) genomes and isometric particles, but approximately 30% have positive sense, single-stranded RNA (+ssRNA) genomes. To be a true mycovirus, they must demonstrate an ability to be transmitted - in other words be able to infect other healthy fungi. Many double stranded RNA elements that have been described in fungi do not fit this description, and in these cases they are referred to as virus like particles or VLPs. Preliminary results indicate that most mycoviruses codiverge with their hosts, i.e. their phylogeny is largely congruent with the one of their hosts. However, many virus families containing mycoviruses have only sparsely been sampled.