Amalgaviridae Explained

Amalgaviridae is a family of double-stranded RNA viruses. Member viruses infect plants and are transmitted vertically via seeds.^[1] The name derives from amalgam (blend, mix) which refers to amalgaviruses possessing characteristics of both partitiviruses and totiviruses.^[2] There are ten species in the family.^[3]

Genome

Amalgavirus genomes are monopartite and about 3.5 kilobases in length.^[4] They have two partially overlapping open reading frames which encode the RNA-dependent RNA polymerase (RdRp) and a putative capsid protein.^[5]

Evolution

It has been suggested that amalgaviruses have evolved via recombination between viruses with double-stranded and negative-strand RNA genomes.^[6] Phylogenetic analysis indicates that the amalgavirus RdRp forms a sister clade to the corresponding RdRp protein of partitiviruses (Partitiviridae) which have segmented (bipartite) dsRNA genomes and infect plants, fungi and protists. By contrast, the putative capsid protein of amalgaviruses is homologous to the nucleocapsid proteins of negative-strand RNA viruses of the genera Phlebovirus (Bunyaviridae) and Tenuivirus.

Taxonomy

The family Amalgaviridae has two genera and ten species:

Amalgavirus

• Allium cepa amalgavirus 1
• Allium cepa amalgavirus 2
• Blueberry latent virus
• Rhododendron virus A
• Southern tomato virus
• Spinach amalgavirus 1
• Vicia cryptic virus M
• Zoostera marina amalgavirus 1
• Zoostera marina amalgavirus 2

Zybavirus

• ''Zygosaccharomyces bailii virus Z

Notes and References

1. Martin. R. R.. Zhou. J. Tzanetakis. I. E.. 2011. Blueberry latent virus: An amalgam of the Partitiviridae and Totiviridae. Virus Research. 155. 1. 175–80. 10.1016/j.virusres.2010.09.020. 20888379.
2. Sabanadzovic. S. Valverde. R. A.. Brown. J. K.. Martin. R. R.. Tzanetakis. I. E.. 2009. Southern tomato virus: The link between the families Totiviridae and Partitiviridae. Virus Research. 140. 1–2. 130–7. 10.1016/j.virusres.2008.11.018. 19118586.
3. Web site: Taxonomy. 21 March 2020. International Committee on Taxonomy of Viruses (ICTV).
4. Sabanadzovic. S. Abou Ghanem-Sabanadzovic. N. Valverde. R. A.. 2010. A novel monopartite dsRNA virus from rhododendron. Archives of Virology. 155. 11. 1859–63. 10.1007/s00705-010-0770-5. 20721591. 13303861.
5. Liu. W. Chen. J. 2009. A double-stranded RNA as the genome of a potential virus infecting Vicia faba. Virus Genes. 39. 1. 126–31. 10.1007/s11262-009-0362-1. 19472044. 10806942.
6. Krupovic M, Dolja VV, Koonin EV. 2015. Plant viruses of the Amalgaviridae family evolved via recombination between viruses with double-stranded and negative-strand RNA genomes. Biol Direct. 10. 1. 12. 10.1186/s13062-015-0047-8. 4377212. 25886840 . free .