Totiviridae

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Totiviridae
Virus classification
Group: Group III (dsRNA)
Family: Totiviridae
Genera

Totiviridae is a family of viruses. Giardia lamblia, leishmania, trichomonas vaginalis, and fungi serve as natural hosts. There are currently 28 species in this family, divided among 5 genera. [1][2]

Taxonomy[edit]

Group: dsRNA

[2]

Structure[edit]

Viruses in Totiviridae are non-enveloped, double-stranded RNA viruses with icosahedral geometries, and T=2 symmetry. The virion consists of a single capsid protein and is about 40 nanometers in diameter.

The genome is composed of a linear double-stranded RNA molecule of 4.6–6.7 kilobases. It contains 2 overlapping open reading frames (ORF)[1]gag and pol—which respectively encode the capsid protein and the RNA-dependent RNA polymerase. Some totiviruses contain a third small potential ORF.

Genus Structure Symmetry Capsid Genomic Arrangement Genomic Segmentation
Giardiavirus Icosahedral T=2 Non-Enveloped Linear Monopartite
Leishmaniavirus Icosahedral T=2 Non-Enveloped Linear Monopartite
Totivirus Icosahedral T=2 Non-Enveloped Linear Monopartite
Victorivirus Icosahedral T=2 Non-Enveloped Linear
Trichomonasvirus Icosahedral T=2 Non-Enveloped Linear

Life Cycle[edit]

Viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. Translation takes place by -1 ribosomal frameshifting, +1 ribosomal frameshifting, viral initiation, and RNA termination-reinitiation. The virus exits the host cell by cell-to-cell movement. Giardia lamblia protozoa, leishmania protozoa, protozoan trichomonas vaginalis, and fungi serve as the natural host.[1]

Genus Host Details Tissue Tropism Entry Details Release Details Replication Site Assembly Site Transmission
Giardiavirus Protozoa None Cell receptor endocytosis Exocytosis Cytoplasm Cytoplasm Passive diffusion
Leishmaniavirus Protozoa: leishmania None Cell receptor endocytosis Cell division Cytoplasm Cytoplasm Cell division
Totivirus Fungi: saccharomyces cerevisiae; fungi: smut fungi None Cytoplasmic exchange, sporogenesis; hyphal anastomosis Cytoplasmic exchange, sporogenesis; hyphal anastomosis Cytoplasm Cytoplasm Cell division; sporogenesis; cell fusion
Victorivirus Fungi None Unknown Unknown Cytoplasm Cytoplasm Unknown
Trichomonasvirus Protozoa Endocytosis Unknown Unknown Cytoplasm Cytoplasm Unknown

References[edit]

  1. ^ a b c "Viral Zone". ExPASy. Retrieved 15 June 2015. 
  2. ^ a b ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. 

External Links[edit]