Reoviridae

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Reoviridae
Rotavirus.jpg

Rotaviruses in the TEM

Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Duplornaviricota
Class : Resentoviricetes
Order : Reovirals
Family : Reoviridae
Taxonomic characteristics
Genome : dsRNA segmented
Baltimore : Group 3
Symmetry : icosahedral
Cover : no
Scientific name
Reoviridae
Left
NCBI  Taxonomy: 10880
ViralZone ( ExPASy , SIB): 104
ICTVdB Virus Code : 00.060

The Reoviridae form the largest family of non-enveloped viruses with double-stranded RNA (dsRNA). Together with the Birnaviridae and Partitiviridae , they are the only viruses whose dsRNA genome is segmented. The family includes such important pathogens as the bluetongue virus , the human rotavirus and the Colorado tick fever virus . Is the name of the family an acronym of " r espiratory, e nteric, o rphan " because it was felt that members of this taxonomic group only bowel disease ( enteric ), respiratory diseases ( respiratory ) or no disease ( orphan ) would cause. In fact, were Reoviridae in many mammals found, as in reptiles , fish , crustaceans and insects . Three genera of the family ( Fijivirus , Phytoreovirus and Oryzavirus ) include pathogens in plants ( plant viruses ) and fungi ( mycoviruses ).

morphology

The mature virus particles (virions) of the Reoviridae are non-enveloped, icosadric capsids with a diameter of about 60-80 nm. Characteristic of most genera of the family (with the exception of the genus Cypovirus ) is the structure of the virion from two nested and closely interacting capsids ( T = 13 ), which in turn surround an inner, regular core structure. The virions, built up from three layers of proteins , therefore show a very typical, thick-walled structure with regular, spoke-shaped thickenings under the electron microscope . Derived from this spoke structure, the genus Rotavirus (lat. Rota : wheel) got its name. This spoke structure is created by 132 openings in the outer capsid, which open into the same number of channels in the inner capsid. These channels, which extend to the inner core, allow ions to diffuse into the virion.
Since the inner core and the inner capsid are responsible for the correct packaging of the RNA segments, the outer capsid can have a relatively large variability of the surface structures without impairing the stability of the virion and the completeness of the genome. Therefore, many reoviruses show numerous species and serotypes .
In the inner core shell is a molecule of the viral RNA polymerase and guanyltransferase . In some genera, myristyl residues (tetradecyl residues) are covalently bound to the capsid. The genera Rotavirus , Orbivirus and Coltivirus occur immature virions that have residues of a lipid envelope. In these genera, the cell leaves the cell by budding on the cell membrane ( orbivirus , coltivirus ) or the membrane of the endoplasmic reticulum (ER) ( rotavirus ). The virions lose the lipid envelope again through an enzymatic maturation step. In some genera, the outer capsid is changed by the host's own proteases (e.g. trypsin , chymotrypsin ), which creates so-called “ infectious subviral particles ” (ISVPs). Only the ISVPs are infectious and the transition of immature virions to ISVPs plays a crucial role in the pathogenesis and the different appearance of the virions in these viruses intestine , saliva or blood serum .

Genome

The genome consists of a double-stranded RNA, which is divided into 10 to 12 segments depending on the genus. The molecular weight of the segments ranges from 0.2 to 3 × 10 6  Da . The Reoviridae viral mRNA does not have a poly-A tail . In some virus species, short, single-stranded RNA oligonucleotides are found in the inner core shell.

Systematics

Internal system

As of November 2018, according to the ICTV, the Reoviriridae are divided as follows (in addition to the type species, only a selection of other species is given):

  • Reoviridae family
  • Macropipus depurator P virus (MdRV-P, DpPV)
  • Carcinus mediterraneus W2 virus (CmRV-W2, CcRV-W2)
  • Species Micromonas pusilla reovirus (en. Micromonas pusilla reovirus , MpRV, type species)
  • Species wound tumor virus (WTV, type species)
  • Species Rice dwarf virus (RDV)
  • Species Rotavirus A (RVA, type species)
  • BoRV-A / UK
  • SiRV-A / SA11
  • Species Rotavirus B (RVB)
  • Hu / MuRV-B / IDIR,
  • Species Rotavirus C (RVC)
  • PoRV-C / Co
  • Species Rotavirus D to I
  • Species Banna virus (en. Banna virus , BAV, type species)
  • Species Liaoning virus ( Liaoning virus , LNV)
  • Species Kadipiro virus (en. Kadipiro virus , KDV)
  • Species aquareovirus A (type species)
  • Species Rotavirus B to G
  • Species Cypovirus 1 (type species)
  • Species Cypovirus 2 to 16
  • Species Aedes pseudoscutellaris virus (en. Aedes pseudoscutellaris virus , officially Aedes pseudoscutellaris reovirus , APRV, type species)
  • Species Fiji disease virus (type species)
  • Species Idnoreovirus 1 (type species)
  • Species Idnoreovirus 2 to 5
  • Species Mycoreovirus 1 (type species)
  • Species Mycoreovirus 2 and 3
  • Species Mammalian orthoreovirus (MRV, type species)
  • Species Rice ragged stunt virus (RRSV, type species)
  • Species Echinochloa ragged stunt virus
Unclassified virus species within the Reoviridae family:
  • SsReV-SZ (SZ-2007) in swimming crabs of the genus Scylla (species Scylla serrata, English mud crab )

The following cladogram is simplifying the relationships again as of the 9th report it International Committee on Taxonomy of Viruses (ICTV, 2011) and MacLachlan / Dubovi (2016); as well as almost consistently by Belhouchet et al. (2010) suggested:

 Reoviridae 
 Sedoreovirinae 

Mimoreovirus (MPrV)


   

Orbivirus ( SCRV , CHUV , AHSV , BTV , KEMV , TRBV , EHDV )


   

Phytoreovirus (RDV)


   


Seadornavirus (LNV, KDV, BAV)


   

Cardoreovirus (ESRV)



   

Rotavirus (RVA, RVB, RVC)






 Spinareovirinae 


Aquareovirus


   

Orthoreovirus (MRV)



   

Idnoreovirus


   

Oryzavirus (RRSV)


   

Dinovernavirus (APRV)


   

Cypovirus




   

Fijivirus


   

Coltivirus ( EYAV , CTFV )


   

Mycoreovirus




Template: Klade / Maintenance / 3



Template: Klade / Maintenance / Style

For some of the genera species, the abbreviated names are specified, they each include one or more of the examined strains associated ( English strains ).

In older studies there are still certain deviations (e.g. in Attoui et al. (2006), Quito-Avila (2011) and Ke et al. (2010).

External system

With the Master Species List # 35 from March 2020, the ICTV assigned the Reoviridae to the newly created Phylum Duplornaviricota . A cladogram can be found at Picornavirales §ICTV Master Species List # 35 .

swell

  • PPC Mertens, C. Wei, B. Hillmann: Family Reoviridae. In: CM Fauquet, MA Mayo et al. : Eighth Report of the International Committee on Taxonomy of Viruses. London, San Diego 2004, pp. 447-555.
  • S. Mordrow, D. Falke, U. Truyen: Molecular Virology. 2nd edition, Heidelberg / Berlin 2003, ISBN 3-8274-1086-X .

Web links

Individual evidence

  1. ↑ ICTV Master Species List 2018b v1 MSL # 34, Feb. 2019
  2. ↑ a b c d e ICTV: Bluetongue virus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. ↑ ICTV : Master Species List 2018a v1 MSL including all taxa updates since the 2017 release. Fall 2018 (MSL # 33)
  4. ↑ a b c d e f ICTV : dsRNA Viruses: Reoviridae , in: ICTV 9th Report (2011), 9th report of the ICTV as a book
  5. ↑ SIB: Orbivirus , on: ViralZone
  6. ↑ SIB: Cypovirus , on: ViralZone
  7. ↑ SIB: Orthoreovirus , on: ViralZone
  8. ↑ Kelly Simone Bateman et al. : A taxonomic review of viruses infecting crustaceans with an emphasis on wild hosts. In: Journal of Invertebrate Pathology. 147, January 2017, doi: 10.1016 / j.jip.2017.01.010
  9. ↑ N. James MacLachlan, Edward J. Dubovi: Fenner's Veterinary Virology. 5th edition 2016, ISBN 978-0-12-800946-8 , doi: 10.1016 / C2013-0-06921-6 .
  10. ↑ Mourad Belhouchet et al. : Complete sequence of Great Island virus and comparison with the T2 and outer-capsid proteins of Kemerovo, Lipovnik and Tribec viruses (genus Orbivirus, family Reoviridae). In: Journal of General Virology. 91 (Pt 12): pp. 2985-2993, December 2010, doi: 10.1099 / vir.0.024760-0
  11. ↑ Houssam Attoui et al: Micromonas pusilla reovirus: A new member of the family Reoviridae assigned to a novel proposed genus (Mimoreovirus). In: Journal of General Virology. 87 (Pt 5), pp. 1375-1383, June 2006, doi: 10.1099 / vir.0.81584-0 .
  12. ↑ Diego F. Quito-Avila et al. : Complete sequence and genetic characterization of Raspberry latent virus, a novel member of the family Reoviridae. In: Virus Research. Volume 155, No. 2, February 2011, pp. 397-405, doi: 10.1016 / j.virusres.2010.11.008 .
  13. ↑ FJ Ke, LB He et al .: Turbot reovirus (SMReV) genome encoding a FAST protein with a non-AUG start site. In: BMC Genomics. 2010, doi: 10.1186 / 1471-2164-12-323 .
  14. ↑ ICTV: ICTV Master Species List 2019.v1 , New MSL including all taxa updates since the 2018b release, March 2020 (MSL # 35)