Narnaviridae is a family of positive single stranded RNA viruses. Members of this family have no capsid. Fungi serve as natural hosts. There are currently seven species in this family, divided among 2 genera.
The genome of these viruses is unipartate and between 2.3 and 3.5 kilobases in length. It encodes a single gene—the RNA dependent RNA polymerase. This protein is associated with the genome in the cytoplasm of the host. The viruses do not have a capsid or envelop and do not form any infectious viral particles except lipid vesicles.
|Genus||Structure||Symmetry||Capsid||Genomic arrangement||Genomic segmentation|
|Mitovirus||No structural proteins||Non-enveloped||Linear||Monopartite|
|Narnavirus||No structural proteins||Non-enveloped||Linear||Monopartite|
Viral replication is cytoplasmic. Replication follows the positive stranded RNA virus replication model. Positive-stranded RNA-virus transcription is the method of transcription. The virus exits the host cell by cell to cell movement. Fungi serve as the natural host. Transmission routes are parental and sexual.
|Genus||Host details||Tissue tropism||Entry details||Release details||Replication site||Assembly site||Transmission|
|Mitovirus||Fungi||None||Horizontal; vertical||None||Cytoplasm||Cytoplasm||Horizontal: mating; vertical: parental|
|Narnavirus||Fungi||None||Horizontal; vertical||None||Cytoplasm||Cytoplasm||Horizontal: mating; vertical: parental|
Two genera have been recognised to date. Mitoviruses infect the mitochondria of fungi while narnaviruses remain within the cytoplasm of the host cell.
Other proposed members of the Mitovirus genus are OnuMV1c and OnuMV7.
Their closest relatives among RNA viruses are plant-infecting viruses of genus Ourmiavirus, which, however, have a capsid and a number of other proteins. Other close relatives are bacteriophages of the family Leviviridae.
- Dolja, V. V.; Koonin, E. V. (2012). "Capsid-Less RNA Viruses". ELS. doi:10.1002/9780470015902.a0023269. ISBN 978-0470016176.
- "Viral Zone". ExPASy. Retrieved 15 June 2015.
- ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
- Solorzano A, Rodríguez-Cousiño N, Esteban R, Fujimura T (2000) Persistent yeast single-stranded RNA viruses exist in vivo as genomic RNA. RNA polymerase complexes in 1:1 stoichiometry. J Biol Chem 275(34):26428–35
- Hillman, B. I.; Cai, G. (2013). "The Family Narnaviridae". Mycoviruses. Advances in Virus Research. 86. pp. 149–76. doi:10.1016/B978-0-12-394315-6.00006-4. ISBN 9780123943156. PMID 23498906.
- Cai G, Myers K, Fry WE, Hillman BI (2011) A member of the virus family Narnaviridae from the plant pathogenic oomycete Phytophthora infestans. Arch Virol
- Hintz W, Kassatenko I, Varga A, James D (2013) Two novel mitoviruses from a Canadian isolate of the Dutch elm pathogen Ophiostoma novo-ulmi (93–1224). Virology Journal 10(252). DOI: 10.1186/1743-422X-10-252