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Descriptions are generated automatically from the ICTVdB database including links. Some descriptions are only very basic and links may point to documents that are not yet published on the Web.

00.012. Caliciviridae

Cite this publication as: ICTVdB Management (2006). 00.012. Caliciviridae. In: ICTVdB - The Universal Virus Database, version 3. Büchen-Osmond, C. (Ed), Columbia University, New York, USA

Cite this site as: ICTVdB - The Universal Virus Database, version 4. http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/

Table of Contents

Classification

This is a description of a vertebrate virus at the family level.

ICTVdB Virus Code: 00.012. Virus accession number: 00012FAM. Obsolete virus code: 12.; superceded accession number: 12000000.
NCBI Taxon Identifier NCBI Taxonomy ID: 11974.

Virion Properties

Morphology

Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 35-39 nm. Capsids appear round to hexagonal in outline. The capsid surface structure reveals a regular pattern with distinctive features. The capsomer arrangement is clearly visible. Capsid with 32 cup-shaped depressions.

caliciviruses. Electron Micrograph by C Büchen-Osmond

Norwalk virus (right and middle) and an unspecified calicivirus (left), bar = 100 nm. Electron Micrograph by C Büchen-Osmond, ICTVdB Management, Columbia University, USA. For enquiries contact C Büchen-Osmond.
Image reconstructions of Norwalk virus (middle, top) by Dr. B.V.Venkataram Prasad's Lab in the W.M. Keck Center for Computational Biology at Baylor College of Medicine. and capsid protein reconstruction (middle, bottom) by VIPER

Physicochemical and Physical Properties

The molecular mass (Mr) of virions is 15 x 106. Virions have a buoyant density in CsCl of 1.33-1.4 g cm-3. The density of virions is in glycerol-potassium tartrate gradients 1.29 g cm-3. The sedimentation coefficient is 170-187 S20w; of the other(s) are peak 160-170 S20w (believed to consist of defective interfering particles). Under in vitro conditions virions are stable in acid environment of pH 4-5. Virions are not stable at raised temperature in presence of high concentration of Mg++. Virions are sensitive to treatment with trypsin (in some strains, not sensitive to treatment with mild detergents, or ether, or chloroform. The infectivity is enhanced after treatment with trypsin (in some strains).

Nucleic Acid

The genome is not segmented and contains a single molecule of linear positive-sense, single-stranded RNA. Minor species of non-genomic nucleic acid are some times also found in virions. The encapsidated nucleic acid is mainly of genomic origin, but virions may also contain subgenomic RNA (in some members). The complete genome is 7400-8300 nucleotides long. The genome has a guanine + cytosine content of 45-56 %. The 5'-end of the genome has a usually genome-linked protein (VPg), or methylated nucleotide cap (in the case of hepatitis E virus). The 3'-terminus has a poly (A) tract. Each virion contains a full length copy, or defective interfering copies.

GenBank records for nucleotide sequences; complete genome sequences.

Proteins

The viral genome encodes structural proteins. Virions consist of 1 structural protein (major species), or 2 structural proteins detected in Norwalk virus, amyelosis chronic stunt virus and porcine enteric calicivirus located in the capsid.

Structural Proteins: Capsid protein has a molecular mass of 58000-60000 Da; is the coat protein. Capsid protein has a molecular mass of minor 'soluble' 28-30 kDa.

Lipids

Lipids are not reported.

Genome Organization and Replication

By itself, genomic nucleic acid is infectious.

Transcription: Sub-genomic RNA is present in infected cells (after infection with e.g., rabbit hemorrhagic disease virus (RHDV)).

Antigenicity

Serological relationships between different members are found (among feline caliciviruses). Cross-reactivity is found. Cross-reactivity between species of the same serotype, but not with species of another serotype and some species of the same serotype, but not with all. Although the degree of antigenic specificity varies with the degree of relatedness, the antigenicity is distinct from canine caliciviruses, Norwalk virus and RHDV serogroups of the same genus.

Biological Properties

Natural Host

Virus infects during its life cycle a single type of vertebrate host.
Domain
Viral hosts belong to the Domain Eucarya.

Domain Eucarya
Kingdom Animalia.

Kingdom Animalia
Phylum Chordata.

Phylum Vertebrata
Subphylum Vertebrata.

Class Mammalia, Aves, Reptilia, and Osteichthyes.

Class Mammalia Order Primates, Carnivora, Perissodactyla, Artiodactyla, and Lagomorphia.

Transmission and Vector Relationships

Virus is not transmitted by a vector.

Histopathology: Virions are found in the cytoplasm.

Geographical Distribution

The virus is probably distributed worldwide, or geographical distribution of the virus is probably restricted (for some species).

Taxonomic Structure of the Family

00.012.0.01. Vesivirus
00.012.0.02. Lagovirus
00.012.0.03. Norovirus
00.012.0.04. Sapovirus.

Unassigned Viruses

List of Unassigned Viruses in the Family.

Data Sources and Contributions

The description has been compiled from data in the ICTV Report presented by Cubitt D, Bradley DW, Carter MJ, Chiba S, Estes MK, Saif LJ, Schaffer FL, Smith AW, Studdert MJ, Thiel HJ.

References

The following generic references are cited in the most recent ICTV Report.

PubMed References. .

Taxonomic Proposals and Changes

Viruses with typical calicivirus morphology have been identified in other animal species including humans, other primates, cattle, mink, swine, walruses, dolphins, dogs, rabbits, chickens, reptiles, amphibians and insects, but none of these have been fully characterized. Those from humans and some other species cause gastroenteritis, and are difficult to propagate in cell culture. Other viruses that cause gastroenteritis in humans, generally designated "small round structured viruses", including Norwalk virus and Snow Mountain agent, lack typical calicivirus morphology, but have buoyant density and a single capsid polypeptide typical of caliciviruses.

Limited serological relationships have been found among strains of viruses from humans: little or no serological relationships have been detected among viruses from other species.

Images

Taxon images: • EM by Cornelia Büchen-Osmond. • EM by Cornelia Büchen-Osmond. • EM from Stewart McNulty, Queens University, Belfast. • EM from Stewart McNulty, Queens University, Belfast. • EM from Dave Bhella, University of Glasgow, Scotland. • EM from Dave Bhella, University of Glasgow, Scotland.



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DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia. ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses by Dr Cornelia Büchen-Osmond is written in DELTA. The virus descriptions in ICTVdB are coded by, or using data from experts in the field of virology or members ICTV. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations are automatically generated and formatted for display on the Web from the descriptions in DELTA-format. The description has been generated automatically from DELTA files. DELTA - DEscription Language for TAxonomy developed by Dr Mike Dallwitz, Toni Paine and Eric Zurcher, CSIRO Entomology, Canberra, Australia.

ICTVdB - The Universal Virus Database, developed for the International Committee on Taxonomy of Viruses (ICTV) by Dr Cornelia Büchen-Osmond, is written in DELTA. The virus descriptions in ICTVdB are coded by ICTV members and experts, or by the ICTVdB Management using data provided by the experts, the literature or the latest ICTV Report. The character list is the underlying code. All virus descriptions are based on the character list and natural language translations from the encoded descriptions are automatically generated and formatted for display on the Web.

Developer of the DELTA software: M. J. Dallwitz, T. Paine and E. Zurcher

ICTVdB and DELTA related References

Comments to ICTVdB Management
Last updated on 25 April 2006 by Cornelia Büchen-Osmond
Copyright © 2002    International Committee on Taxonomy of Viruses.    All rights reserved.


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