Tymoviridae

Tymoviridae
Virus classification
Group: Group IV ((+)ssRNA)
Order: Tymovirales
Family: Tymoviridae
Genera

Tymoviridae is a family of single-stranded positive sense RNA viruses in the order Tymovirales. Plants serve as natural hosts. There are currently 37 species in this family, divided among 3 genera.[1][2]

Taxonomy

The largest of three genera is Tymovirus with 27 species, whereas the other genera, Marafivirus and Maculavirus have 7 and 1 species respectively.[2]

Group: ssRNA(+)

[2]

Proposed Viruses

Virology

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.

Genus Structure Symmetry Capsid Genomic Arrangement Genomic Segmentation
MaculavirusIcosahedralT=3Non-EnvelopedLinearMonopartite
MarafivirusIcosahedralT=3Non-EnvelopedLinearMonopartite
TymovirusIcosahedralT=3Non-EnvelopedLinearMonopartite

Life Cycle

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
MaculavirusPlantsNoneViral movement; mechanical innoculationViral movementCytoplasmCytoplasmMechanical inoculation: pseudococcid mealybugs; Mechanical inoculation: aphids
MarafivirusPlantsNoneViral movement; mechanical innoculationViral movementCytoplasmCytoplasmMechanical inoculation: pseudococcid mealybugs; Mechanical inoculation: aphids
TymovirusPlantsNoneViral movement; mechanical innoculationViral movementCytoplasmCytoplasmMechanical: beetles; sap

References

  1. 1 2 3 4 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. 1 2 3 ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
  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

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