Rhabdoviridae
Encyclopedia
Rhabdoviruses are virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es belonging to the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Rhabdoviridae, which is in the order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Mononegavirales
Mononegavirales
The order Mononegavirales is the taxonomic home of numerous related viruses. Members of the order that are commonly known are, for instance, Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah virus, and rabies virus. All of these viruses cause significant disease in...

. 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 kingdoms. Animal rhabdoviruses infect insects, fish, and mammals, including humans.

Virology Classification

Rhabdoviruses carry their genetic material in the form of negative-sense single-stranded RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

. They typically carry genes for five proteins: large protein (L), glycoprotein (G), nucleoprotein (N), phosphoprotein (P), 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
    Lettuce necrotic yellows virus
    Lettuce necrotic yellows virus is a plant virus belonging to the virus order Mononegavirales, family Rhabdoviridae and genus cytorhabdovirus. It was first identified in Australia in the plant species Lactuca sativa in 1963 by Stubbs et al. Since then it has been identified in many other plant...

  • Genus Dichorhabdovirus; type species: Orchid fleck virus
  • Genus Ephemerovirus; type species: Bovine ephemeral fever virus
  • Genus Lyssavirus
    Lyssavirus
    Lyssavirus is a genus of viruses belonging to the family Rhabdoviridae, in the order Mononegavirales. This group of RNA viruses includes the Rabies virus traditionally associated with the disease.-Structure:Viruses typically have either helical or cubic symmetry...

    ; type species: Rabies
    Rabies
    Rabies is a viral disease that causes acute encephalitis in warm-blooded animals. It is zoonotic , most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure prophylaxis is not administered prior to the onset of severe symptoms...

     virus
  • Genus Novirhabdovirus
    Novirhabdovirus
    Novirhabdovirus is one of the genera of Rhabdoviridae, along with Vesiculovirus, known to infect aquatic hosts. They can be transmitted from fish to fish, by waterborne virus, as well as through contaminated eggs. Replication and thermal inactivation temperatures are generally lower than for other...

    ; type species: Infectious hematopoietic necrosis virus
    Infectious hematopoietic necrosis virus
    -Introduction:Infectious hematopoietic necrosis virus , is a negative-sense single-stranded, bullet-shaped RNA virus that is a member of the Rhabdoviridae family, and from the genus Novirhabdovirus. It causes the disease known as infectious hematopoietic necrosis in salmonid fish like trout and...

  • Genus Nucleorhabdovirus; type species: Potato yellow dwarf virus
    Potato yellow dwarf virus
    Potato yellow dwarf virus is a plant virus of order Mononegavirales, family Rhabdoviridae and genus Nucleorhabdovirus. The virus was first identified in 1922 in the USA by Barrus and Chupp who reported it having an effect on the plant species Solanum tuberosum...

  • Genus Vesiculovirus; type species: Vesicular stomatitis Indiana virus
    Vesicular stomatitis virus
    Vesicular stomatitis Indiana virus is a virus in the family Rhabdoviridae; the well-known Rabies virus belongs to the same family. VSIV can infect insects, cattle, horses, pigs and humans. It has particular importance to farmers in certain regions of the world where it can infect cattle...



In addition to the above, there are a large number of rhabdoviruses that have not yet been assigned to a genus.

Replication

Replication of many rhabdoviruses occurs in the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

, although several of the plant infecting viruses replicate in the nucleus. In order for replication, both the L and P protein must be expressed to regulate transcription
Transcription (genetics)
Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

. Transcription results in five monocistronic mRNAs being produced because the intergenic sequences
Intergenic region
An Intergenic region is a stretch of DNA sequences located between clusters of genes that contain few or no genes. Occasionally some intergenic DNA acts to control genes nearby, but most of it has no currently known function...

 act as both termination
Terminator (genetics)
In genetics, a terminator, or transcription terminator is a section of genetic sequence that marks the end of gene or operon on genomic DNA for transcription.In prokaryotes, two classes of transcription terminators are known:...

 and promoter sequences for adjacent genes
Gênes
Gênes is the name of a département of the First French Empire in present Italy, named after the city of Genoa. It was formed in 1805, when Napoleon Bonaparte occupied the Republic of Genoa. Its capital was Genoa, and it was divided in the arrondissements of Genoa, Bobbio, Novi Ligure, Tortona and...

. During their synthesis the mRNAs are processed to introduce a 5' cap
5' cap
The 5' cap is a specially altered nucleotide on the 5' end of precursor messenger RNA and some other primary RNA transcripts as found in eukaryotes. The process of 5' capping is vital to creating mature messenger RNA, which is then able to undergo translation...

 and a 3’ polyadenylated tail
Polyadenylation
Polyadenylation is the addition of a poly tail to an RNA molecule. The poly tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In eukaryotes, polyadenylation is part of the process that produces mature messenger RNA for translation...

 to each of the molecules. This structure is homologous to cellular mRNAs and can thus be translated
Translation (genetics)
In molecular biology and genetics, translation is the third stage of protein biosynthesis . In translation, messenger RNA produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein...

 by cellular ribosomes to produce both structural and non-structural proteins.

Genomic
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

 replication requires a source of newly synthesized N protein to encapsidate the RNA. This occurs during its synthesis and results in the production of a full length anti-genomic copy. This in turn is used to produce more negative-sense genomic RNA. The viral polymerase is required for this process, but how the polymerase engages in both mRNA synthesis and genomic replication is not well 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
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

.

Prototypical Rhabdoviruses

The prototypical and best studied rhabdovirus is vesicular stomatitis virus
Vesicular stomatitis virus
Vesicular stomatitis Indiana virus is a virus in the family Rhabdoviridae; the well-known Rabies virus belongs to the same family. VSIV can infect insects, cattle, horses, pigs and humans. It has particular importance to farmers in certain regions of the world where it can infect cattle...

. It is a preferred model system to study the biology of Rhabdoviruses, and Mononegavirales
Mononegavirales
The order Mononegavirales is the taxonomic home of numerous related viruses. Members of the order that are commonly known are, for instance, Ebola virus, human respiratory syncytial virus, measles virus, mumps virus, Nipah virus, and rabies virus. All of these viruses cause significant disease in...

 in general.

The mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

ian disease Rabies
Rabies
Rabies is a viral disease that causes acute encephalitis in warm-blooded animals. It is zoonotic , most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure prophylaxis is not administered prior to the onset of severe symptoms...

 is caused by Lyssavirus
Lyssavirus
Lyssavirus is a genus of viruses belonging to the family Rhabdoviridae, in the order Mononegavirales. This group of RNA viruses includes the Rabies virus traditionally associated with the disease.-Structure:Viruses typically have either helical or cubic symmetry...

, 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



christina vargas
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