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.
00.073. Togaviridae
Cite this publication as: ICTVdB Management (2006).
00.073. Togaviridae. 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/
This is a description of an
invertebrate or vertebrate virus at the family
level.
ICTVdB Virus Code: 00.073. Virus accession number: 00073FAM.
Obsolete virus code: 73.; superceded accession number: 73000000.
NCBI Taxon Identifier NCBI Taxonomy ID:
11018.
Virions consist of an envelope and a nucleocapsid. During
their life cycle, virions have not been observed outside a cellular environment
and have a cell-associated cycle. Virus capsid is tightly enveloped by
a detergent sensitive lipoprotein. Virions are spherical to pleomorphic. Virions
measure 70 nm in diameter. Surface projections are distinctive
glycoprotein spikes that cover evenly the
surface. Capsid/nucleocapsid is round and exhibits icosahedral
symmetry (T=4. The isometric capsid has a diameter of 40 nm. Capsids appear round.
The molecular mass (Mr) of virions is 52 x 106.
Virions have a buoyant density in sucrose of 1.18-1.2 g
cm-3. The sedimentation coefficient is 280
S20w. The thermal inactivation point (TIP) is at 58°C.
The longevity in vitro (LIV) is 0.35 days (at 37°C in culture
medium). Under in vitro conditions virions are stable in
alkaline environment of pH 7-8. Virions are sensitive to treatment with
organic solvents and detergents (which solubilzes their lipoprotein envelops).
The infectivity is reduced after exposure to irradiation.
The
genome is not segmented and contains a single molecule of linear
positive-sense, single-stranded RNA. The complete
genome is 9700-11800 nucleotides long. The 5'-end of the genome has a
methylated nucleotide cap. The 3'-terminus has a poly (A) tract.
GenBank records for
nucleotide sequences;
complete genome sequences.
The viral
genome encodes structural proteins and non-structural proteins. Virions consist
of 3 structural protein(s), or 4 structural protein(s).
Lipids are
present and located in the envelope. Virions are composed of 30%
lipids by weight. The composition of viral lipids and host cell membranes are
similar. The lipids are of host origin and are derived from host
cell membranes. Viral membranes include phosphatidyl ethanolamine,
phosphatidyl choline, phosphatidyl serine, cholesterol, and sphingomyelin.
Genome Organization and Replication
Serological relationships
between different members are considerable. Homologies can be identified in
amino acid sequences of the coat protein of non-vector transmitted viruses (of
about 40%). Cross-reactivity is found. Cross-reactivity between species, but not
genera. Species that are serologically interrelated have antigenic homologies
with different species of the same serogroup or complex. Although the degree of
antigenic specificity varies with the degree of relatedness, the antigenicity is
from alphaviruses distinct from (rubella virus). Classification of members of
this taxon is based on their antigenic properties (initially).
Natural Host
Virus infects during its life cycle arthropod and vertebrate hosts. Domain
Viral hosts belong to the Domain Eucarya.
Domain Eucarya
Kingdom Animalia.
Kingdom Animalia
Phylum Arthropoda and
Chordata.
Phylum Vertebrata
Subphylum Vertebrata.
Class Aves, or Mammalia.
Class Mammalia Order Primates;
Family
Hominidae.
Virus infects Homo sapiens (human).
Virus is transmitted by a vector, or not transmitted by a
vector.
Vector Transmission:
Virus is transmitted by arthropods, insects. Virus replicates in the vector.
Histopathology: Virions are found in the cytoplasm.
The virus is probably distributed worldwide.
00.073.0.01.
Alphavirus
00.073.0.02.
Rubivirus.
Data Sources and
Contributions
The
following generic references are cited in the most recent ICTV Report.
PubMed References. at
Virology Down Under.
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