00.109. Marnaviridae - ICTVdB Index of Viruses

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Nature of Genome:
General Host Type:
Morphology:

positive-stranded ssRNA
Algae
isometric

Family	00.109. Marnaviridae
	Taxonomic Structure of the Family
	Family 00.109. Marnaviridae Genus 00.109.0.01. Marnavirus

Genus	00.109.0.01. Marnavirus
Type Species	00.109.0.01.001. Heterosigma akashiwo RNA virus

List of Species Demarcation Criteria in the Genus

Not applicable.

List of Species in the Genus

The ICTVdB virus code and the viruses. Official virus species names are in italics. Tentative virus species names, alternative names ( ), isolates, strains, serotypes, subspecies, or rejected names are not italicized.

Virus codes, virus names, genome sequence accession numbers [ ] and assigned abbreviations ( ), are:

Species, their serotypes, strains and isolates

00.109.0.01.001.	Heterosigma akashiwo RNA virus		(HaRNAV)
00.109.0.01.001.00.001.	Heterosigma akashiwo RNA virus SOG263	[AY337486]	(HaRNAV-SOG263)

Tentative Species in the Genus

None reported.

List of Unassigned Viruses in the Family

None reported.

Similarity with other Taxa

There is strong evidence placing the family Marnaviridae in the "picorna-like superfamily". The HaRNAV genome is composed of one molecule of ssRNA of positive sense that exhibits the 2C-3Cpro-3Dpol gene order and particles are icosahedral with a diameter ~25 nm, a size and structure consistent with picorna-like viruses. However, the structure of the viral genome and the patterns of sequence relationships of HaRNAV proteins to other known viral picorna-like proteins clearly show that it does not belong in any of the currently established picorna-like families. The HaRNAV genome structure is mostly like the potyviruses (e.g., Tobacco etch virus), in that the non-structural protein domains are located at the N-terminus and the structural proteins are at the C-terminus in a single large polyprotein encoded on a monopartite genome. However, potyvirus capsids are filamentous and phylogenetic analyses demonstrated no significant homology with this family. Moreover, a phylogenetic analysis of picorna-like RdRps does not place the HaRNAV sequence within any established family of picorna-like viruses. It is not surprising that HaRNAV represents a new family as it is the first picorna-like virus that has been described that infects a protist.

Derivation of Names

Marna is a sigla derived from mare: Latin, "sea", and RNA

Contributed by

Culley, A.I., Lang, A.S. and Suttle, C.A.

Cite this publication as: Index of Viruses - Marnaviridae (2006). In: ICTVdB - The Universal Virus Database, version 4. Büchen-Osmond, C (Ed), Columbia University, New York, USA. http://www.ncbi.nlm.nih.gov/ICTVdb/Ictv/fs_index.htm

Version 4 is based on Virus Taxonomy, Classification and Nomenclature of Viruses, 8th ICTV Report of the International Committee on Taxonomy of Viruses. Fauquet, CM, Mayo, MA, Maniloff, J, Desselberger, U, and Ball, LA (EDS) (2005) Elsevier/Academic Press, pp. 1259.

Additional References

Species List and Reference List from the 8th ICTV Report
ICTVdB taxon description

References to sequence databases at GenBank and PubMed Central:
PubMed Central References; nucleotide sequences; complete genomes

Additional access points to virus species lists, descriptions and images on the web: