''Cripavirus'' is a genus of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room ...

in the order ''

Picornavirales ''Picornavirales'' is an order of viruses with vertebrate, invertebrate, protist and plant hosts. The name has a dual etymology. First, ''picorna-'' is an acronym for poliovirus, insensitivity to ether, coxsackievirus, orphan virus, rhinovirus ...

'', in the family ''

Dicistroviridae ''Dicistroviridae'' is a family of viruses in the order ''Picornavirales''. Invertebrates, including aphids, leafhoppers, flies, bees, ants, and silkworms, serve as natural hosts. There are 15 species in this family, assigned to three genera. Di ...

''. Invertebrates serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: DCV: increased reproductive potential; extremely pathogenic when injected with high associated mortality; CrPV: paralysis and death. These viruses can produce proteins directly from their RNA genome upon entering a cell; and therefore, does not require an RNA polymerase packaged in with it, as this may be produced from the genome after entering the cell.International Committee on the Taxonomy of Viruses
The name of the cripavirus family originates from its most famous member the Cricket Paralysis Virus. Which was made famous by its rather unusual IRES (Internal Ribosome Entry Site): the

Cripavirus IRES The Cripavirus internal ribosome entry site (CrPV IRES) is an RNA element required for the production of capsid proteins through ribosome recruitment to an intergenic region IRES (IGR IRES). See also * Cricket paralysis virus * Internal ...

. The Cripavirus IRES is an RNA element that allows the virus to bind the ribosome and translate without a need for any initiation factors – as initiation is the most regulated step of translation this allows the virus to avoid many mechanisms to inhibit viral activity.

Taxonomy

The genus contains the following species: *'' Aphid lethal paralysis virus'' *''

Cricket paralysis virus Cricket paralysis virus (CrPV) was initially discovered in Australian field crickets ('' Teleogryllus commodus'' and '' Teleogryllus oceanicus'') by Carl Reinganum and his colleagues at the Victorian Plant Research Institute (Burnley, Melbourne, ...

'' *'' Drosophila C virus'' *''

Rhopalosiphum padi virus Rhopalosiphum padi virus (RhPV) is a member of '' Dicistroviridae'' family, which includes cricket paralysis virus (CrPV), ''Plautia stali'' intestine virus and ''Drosophila'' C virus. Its 5'UTR region contains an internal ribosome entry site A ...

Structure

Viruses in ''Cripavirus'' are non-enveloped, have

capsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may ...

s of 12

capsomer The capsomere is a subunit of the capsid, an outer covering of protein that protects the genetic material of a virus. Capsomeres self-assemble to form the capsid. Subunits called protomers aggregate to form capsomeres. Various arrangements of ca ...

s, and have icosahedral geometries with T=pseudo3 symmetry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 8.5–10.2kb in length, and has a VPg (genome linked viral protein) on the 5' end. The

5' end Directionality, in molecular biology and biochemistry, is the end-to-end chemical orientation of a single strand of nucleic acid. In a single strand of DNA or RNA, the chemical convention of naming carbon atoms in the nucleotide pentose-sugar- ...

also has a series of C's near it, while the

3' end Directionality, in molecular biology and biochemistry, is the end-to-end chemical orientation of a single strand of nucleic acid. In a single strand of DNA or RNA, the chemical convention of naming carbon atoms in the nucleotide pentose-sugar- ...

has a series of A's near it. The genome has 2 open reading frames.

Life cycle

Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method of transcription. Translation takes place by viral initiation, and ribosomal skipping. Invertebrates serve as the natural host. Transmission routes are contamination.

References

External links

Viralzone: Cripavirus

ICTV
{{Taxonbar, from=Q5185820 Dicistroviridae Virus genera