Tymoviridae is a family of single-stranded positive sense RNA viruses in the order Tymovirales. Plants serve as natural hosts. There are 42 species in this family, assigned to three genera, with two species unassigned to a genus.[1][2]

Tymoviridae
Virus classification Edit this classification
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Kitrinoviricota
Class: Alsuviricetes
Order: Tymovirales
Family: Tymoviridae
Genera
Turnip yellow mosaic virus on cabbage

Taxonomy

edit

The family includes the following three genera:[2]

Additionally, the following two species are not assigned to a genus:[2]

Proposed viruses

edit

Virology

edit

The virions are non-enveloped and isometric with a diameter of around 30 nm, with an icosahedral structure and a triangulation number T=3.[1]

The linear genome is between of 6–7.5 kilobases in length[1] and encodes one large open reading frame. It is capped at the 5’ terminus. The 3’ terminus may have a tRNA-like structure or a polyA tract, depending upon the species. The genome is relatively cytosine rich.[citation needed]

Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentation
Maculavirus Icosahedral T=3 Non-enveloped Linear Monopartite
Marafivirus Icosahedral T=3 Non-enveloped Linear Monopartite
Tymovirus Icosahedral T=3 Non-enveloped Linear Monopartite

Life cycle

edit

Viral replication is cytoplasmic, and is lysogenic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Translation takes place by leaky scanning. The virus exits the host cell by monopartite non-tubule guided viral movement. Plants serve as the natural host. The virus is transmitted via a vector (insects). Transmission routes are vector and mechanical.[1]

Genus Host details Tissue tropism Entry details Release details Replication site Assembly site Transmission
Maculavirus Plants None Viral movement; mechanical inoculation Viral movement Cytoplasm Cytoplasm Mechanical inoculation: pseudococcid mealybugs; Mechanical inoculation: aphids
Marafivirus Plants None Viral movement; mechanical inoculation Viral movement Cytoplasm Cytoplasm Mechanical inoculation: pseudococcid mealybugs; Mechanical inoculation: aphids
Tymovirus Plants None Viral movement; mechanical inoculation Viral movement Cytoplasm Cytoplasm Mechanical: beetles; sap

References

edit
  1. ^ a b c d "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. ^ a b c "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 15 May 2021.
  3. ^ Wang L, Lv X, Zhai Y, Fu S, Wang D, Rayner S, Tang Q, Liang G (2012) Genomic characterization of a novel virus of the family tymoviridae isolated from mosquitoes. PLoS One 7(7):e39845.

Further reading

edit
  • Martelli GP. Sabanadzovic S. Abou-Ghanem Sabanadzovic N. Edwards MC. Dreher T. (2002). The family Tymoviridae. Archives of Virology. 147(9):1837-46
  • University of Leicester Microbiology
edit