''Fijivirus'' is a genus of

double-stranded RNA viruses Double-stranded RNA viruses (dsRNA viruses) are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA pol ...

in the family ''

Reoviridae ''Reoviridae'' is a family of double-stranded RNA viruses. Member viruses have a wide host range, including vertebrates, invertebrates, plants, protists and fungi. They lack lipid envelopes and package their segmented genome within multi-layered ...

'' and subfamily ''

Spinareovirinae ''Spinareovirinae'' is a subfamily of double-stranded RNA viruses in the family ''Reoviridae''. Viruses in this group are distinguished by the presence of a turreted protein on the inner capsid. (''Spina'' = spiny or thorny in Latin.) Taxonomy ...

.'' Plants serve as natural hosts. Diseases associated with this genus include: galls (tumours) in infected plants and Fiji disease, with severe stunting, deformation and death. The group name derives from ''Fiji'' island the place where the first virus was isolated. There are nine species in this genus.

Structure

Fijivirus genome composition contains ten linear double-stranded RNA (dsRNA) and is carried within virus particles referred to as virions. The Fijivirus genome is constructed inside the virion and is non-

envelope An envelope is a common packaging item, usually made of thin, flat material. It is designed to contain a flat object, such as a letter or card. Traditional envelopes are made from sheets of paper cut to one of three shapes: a rhombus, a shor ...

d. It contains two separate layers of capsids, an inner and an outer layer, which are constructed by proteins that shell the virus. The capsids are of

icosahedral symmetry In mathematics, and especially in geometry, an object has icosahedral symmetry if it has the same symmetries as a regular icosahedron. Examples of other polyhedra with icosahedral symmetry include the regular dodecahedron (the dual of the ...

(T=2 for inner capsid, T=13 for outer capsid), and have an obvious round structure, which is on average 65–70 nm in diameter. Genomes are linear and segmented, around 4.5 kbp in length. The genome codes for 12 proteins.

Replication

Replications of the Fijivirus occurs within the

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...

; the virus will diffuse through the cytoplasm of the cell.

Transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, the fir ...

of the dsRNA genome occurs inside the virion, and this is important so that the dsRNA is not exposed to the cytoplasm. Transcription results in a positive strand that is then used as the template for

translation Translation is the communication of the Meaning (linguistic), meaning of a #Source and target languages, source-language text by means of an Dynamic and formal equivalence, equivalent #Source and target languages, target-language text. The ...

. The positive RNAs become enclosed within the virion, and then are transcribed to give RNA molecules. With the newly formed molecule, it then becomes

base-pair A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

ed to produce the dsRNA genomes as described above. Mature virions are released following cell death and the breakdown of the affected hosts plasma

membrane A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. B ...

.Major source for information was retrieved from http://viralzone.expasy.org/all_by_species/612.html

Transmission

The virus is transmitted by

planthoppers A planthopper is any insect in the infraorder Fulgoromorpha, in the suborder Auchenorrhyncha, a group exceeding 12,500 described species worldwide. The name comes from their remarkable resemblance to leaves and other plants of their environment ...

, which are insects, or other types of organisms. The virus will infect the phloem tissues of its plant ( Gramineae and Liliacea) hosts. If the presence of a

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

appears, usually located on specific parts of the plant, it can represent the first sign of the virus (Pearson 2004). Replication can occur both in the host and the vector. The plant is unable to recover from the unexpected growth and therefore can become stunted, and can eventually die.

Taxonomy

The genus has nine species: *''

Fiji disease virus Fiji disease virus (FDV) belongs to the reoviridae family and infects plants. It is one of the few plant viruses in the Reoviridae family. The type species of the genus '' Fijivirus'', it is the only known member of Fijivirus group 1. Fiji dis ...

'' *'' Garlic dwarf virus'' *'' Maize rough dwarf virus'' *'' Mal de Rio Cuarto virus'' *'' Nilaparvata lugens reovirus'' *'' Oat sterile dwarf virus'' *'' Pangola stunt virus'' *'' Rice black streaked dwarf virus'' *'' Southern rice black-streaked dwarf virus''

References

External links

Viralzone: Fijivirus

ICTV
* ICTVdb Management. (2002). ''00.060.0.07. Fijivirus.'' Retrieved from https://web.archive.org/web/20120425154205/http://ictvdb.bio-mirror.cn/ICTVdB/00.060.0.07.htm * ''Notes on Genus: Fijivirus.'' (n.d). Retrieved from http://www.dpvweb.net/notes/showgenus.php?genus=Fijivirus * Ecoport. (2004). ''Sugarcane Fiji Disease Fijivirus.'' Retrieved from http://ecoport.org/ep?Virus=25040&entityType=VI****&entityDisplayCategory=VI****0500 {{Taxonbar, from=Q5448211 Virus genera Spinareovirinae