''Barnaviridae'' is a family of non-enveloped,

positive-strand RNA virus Positive-strand RNA viruses (+ssRNA viruses) are a group of related viruses that have positive-sense, single-stranded genomes made of ribonucleic acid. The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated int ...

es. Cultivated

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is t ...

s serve as natural hosts. The family has one genus, ''Barnavirus'', which contains one species: ''Mushroom bacilliform virus''. Diseases associated with this family includes La France disease.

Structure

Viruses in ''Barnaviridae'' are non-enveloped, with icosahedral and Bacilliform geometries, and T=1 symmetry. These viruses are about 50 nm long.

Genome

Genomes are linear, around 4kb in length. The genome has 4 open reading frames. Genomic RNA serves as both the genome and viral messenger RNA. ORF2 is a polyprotein which is possibly auto-cleaved by the ORF2 viral protease. ORF3 encodes the RNA dependent RNA polymerase and may be translated by ribosomal frameshifting as an ORF2-ORF3 polyprotein. The single capsid protein (ORF4) is translated from a subgenomic RNA.

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell and passing it down. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. The virus is released horizontal via

mycelium Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrate (biology), substrates. A typical single ...

and

basidiospore A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pro ...

s. Cultivated mushroom, ''

Agaricus bisporus ''Agaricus bisporus'' is an edible basidiomycete mushroom native to grasslands in Eurasia and North America. It has two color states while immature – white and brown – both of which have various names, with additional names for the mature ...

'', serves as the natural host.

References

External links

Viralzone: Barnaviridae

ICTV
{{Taxonbar, from=Q3772886 Mycology Virus families Riboviria