RHABDOVIRIDAE

''Vesiculovirus''

''Lyssavirus''

''Ephemerovirus''

''Cytorhabdovirus''

''Nucleorhabdovirus''

''Novirhabdovirus''
'Rhabdoviruses' are viruses belonging to the family ''Rhabdoviridae'', which is in the order ''Mononegavirales''. The name is derived from the Greek rhabdos meaning rod referring to the shape of the viral particles. Rhabdoviruses infect a broad range of hosts throughout the animal and plant kingdom. Animal rhabdoviruses infect insects, fish, and mammals, including humans.

Contents

The Viruses

Replication

Prototypical Rhabdoviruses

Further reading

External links

The Viruses

Rhabdoviruses carry their genetic material in the form of negative-sense single-stranded RNA. They typically carry genes for five proteins: large protein (L), glycoprotein (G), nucleoprotein (N), nonstructural protein (NS), and matrix protein (M). Rhabdoviruses that infect vertebrates are bullet-shaped.
The following genera are included here:

★ Genus ''Cytorhabdovirus''; type species: ''Lettuce necrotic yellows virus''

★ Genus ''Ephemerovirus''; type species: ''Bovine ephemeral fever virus''

★ Genus ''Lyssavirus''; type species: ''Rabies virus''

★ Genus ''Novirhabdovirus''; type species: ''Infectious hematopoietic necrosis virus''

★ Genus ''Nucleorhabdovirus''; type species: ''Potato yellow dwarf virus''

★ Genus ''Vesiculovirus''; type species: ''Vesicular stomatitis Indiana virus''
In addition to the above, there are a large number of rhabdoviruses that have not yet been assigned to a genus.

Replication

Replication of rhabdoviruses occurs in the cytoplasm. In order for replication, both the L and NS protein must be expressed to regulate transcription. Transcription results in five monocistronic mRNAs being produced because the intergenic sequences act as both termination and promoter sequences for adjacent genes. Subsequently, the mRNAs are then processed to introduce a 5’ cap and a 3’ polyadenylated tail to each of the molecules. This structure is homologous to cellular mRNAs and can thus be translated by cellular ribosomes to produce both structural and non-structural proteins.
Genomic replication is not as well understood. It is believed that, once the various proteins have been synthesised, a full length genomic copy is generated and subsequently replicated from a positive sense intermediate. It has been shown that the L+P polymerase complex is necessary. Nevertheless cellular factors are also required, but these are not fully understood.
Replication characteristically occurs in an inclusion body within the cytoplasm, from where they bud through various cytoplasmic membranes and the outer membrane of the cell. This process results in the acquisition of the M + G proteins, responsible for the characteristic bullet- shaped morphology of the virus.

Prototypical Rhabdoviruses

The prototypical and best studied rhabdovirus is vesicular stomatitis virus. Since it is easy to grow in the laboratory, it is a preferred model system to study the biology of Rhabdoviruses, and Mononegavirales in general.
The mammalian disease Rabies is caused by ''Lyssavirus'', of which several strains have been identified.
Rhabdoviruses are important pathogens of animals and plants. Rhabdoviruses include RaV (Rabies virus), VSV (Vesicular stomatitis virus). Rhabdoviruses are transmitted to hosts by arthropods, such as aphids, planthoppers, leafhoppers, black flies, sandflies, and mosquitoes.

Further reading

★ J.K. Rose and M.A. Whitt (2001). Rhabdoviridae: The viruses and their replication. In: D.M. Knipe and P.M. Howley, ed., Field's Virology, vol. 1, pp. 1221-1244. Lippincott Williams & Wilkins, Philadelphia, 4th edition.

★ R.R. Wagner, ed. (1987). The Rhabdoviruses. Plenum Press, New York.

External links

★ MicrobiologyBytes: Rhabdoviruses

★ Rhabdovirus overview

★ RNA virus replication strategies