''Marnaviridae'' is a family of

positive-stranded In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, ...

RNA virus An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...

es in the order ''

Picornavirales ''Picornavirales'' is an order of viruses with vertebrate, invertebrate, protist and plant hosts. The name has a dual etymology. First, ''picorna-'' is an acronym for poliovirus, insensitivity to ether, coxsackievirus, orphan virus, rhinovirus, ...

''. The first species of this family that was isolated is ''Heterosigma akashiwo RNA virus'' (HaRNAV) in the genus ''

Marnavirus ''Marnaviridae'' is a family of positive-stranded RNA viruses in the order ''Picornavirales''. The first species of this family that was isolated is ''Heterosigma akashiwo RNA virus'' (HaRNAV) in the genus '' Marnavirus'', that infects the toxi ...

'', that infects the toxic bloom-forming

Raphidophyte The raphidophytes, formally known as Raphidomonadea or Raphidophyceae (formerly referred to as Chloromonadophyceae and Chloromonadineae), are a small group of eukaryotic algae that includes both marine and freshwater species. All raphidophytes ...

alga, ''

Heterosigma akashiwo ''Heterosigma akashiwo'' is a species of microscopic algae of the class Raphidophyceae. It is a swimming marine alga that episodically forms toxic surface aggregations known as harmful algal bloom. The species name ''akashiwo'' is from the Japa ...

''. Using a sequence-based framework an additional twenty marine RNA viruses have been added to the family. HaRNAV was isolated from water collected in the

Strait of Georgia The Strait of Georgia (french: Détroit de Géorgie) or the Georgia Strait is an arm of the Salish Sea between Vancouver Island and the extreme southwestern mainland coast of British Columbia, Canada and the extreme northwestern mainland coast ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, Canada, from a concentrated virus assemblage using the host ''Heterosigma akashiwo'' (NEPCC 522). It must not be confused with two other unrelated viruses that infect this host, ''Heterosigma akashiwo virus 01'' (HaV-1, isolate: HaV53) in the genus ''

Raphidovirus ''Raphidovirus'' (likely misspelled ''Rhaphidovirus'') is a genus of viruses, in the family ''Phycodnaviridae ''Phycodnaviridae'' is a family of large (100–560 kb) double-stranded DNA viruses that infect marine or freshwater eukaryot ...

'', and '' Heterosigma akashiwo Nuclear Inclusion Virus'' (HaNIV).

Taxonomy

The family contains the following seven genera: *'' Bacillarnavirus'' *'' Kusarnavirus'' *'' Labyrnavirus'' *'' Locarnavirus'' *''

'' *'' Salisharnavirus'' *'' Sogarnavirus''

Structure

Virions in ''Marnaviridae'' are non-enveloped, with icosahedral geometries, and T=pseudo3 symmetry. The diameter is around 25 nm. Genomes are linear and non-segmented (monopartit), around 8.6 kb in length. The capsid consists of three major capsid proteins (MCPs: VP1, VP2, VP3), each having a

Jelly roll fold The jelly roll or Swiss roll fold is a protein fold or supersecondary structure composed of eight beta strands arranged in two four-stranded sheets. The name of the structure was introduced by Jane S. Richardson in 1981, reflecting its resemblance ...

and a minor capsid protein (mCP) that is located around the five-fold axes on the inside of the capsid.

Life cycle

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. The virus exits the host cell by tubule-guided viral movement. Marine

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

serve as the natural hosts of the only known member of the family ''Marnaviridae''.

References

External links

Viralzone: Marnaviridae

ICTV
* NCBI
Marnaviridae
(family) * ICTV
Taxonomy History – ''Marnaviridae''
{{Taxonbar, from=Q15642831 Picornavirales Virus families