''Dicistroviridae'' is a family of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...

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, ...

''. Invertebrates, including

aphids Aphids are small sap-sucking insects in the Taxonomic rank, family Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white Eriosomatinae, woolly ...

, leafhoppers,

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

bees Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

ants Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

, and

silkworm ''Bombyx mori'', commonly known as the domestic silk moth, is a moth species belonging to the family Bombycidae. It is the closest relative of '' Bombyx mandarina'', the wild silk moth. Silkworms are the larvae of silk moths. The silkworm is of ...

s, serve as natural hosts. There are 16 species in this family, assigned to three genera. Diseases associated with this family include: DCV: increased reproductive potential. extremely pathogenic when injected with high associated mortality. CrPV: paralysis and death.

Taxonomy

Although many dicistroviruses were initially placed in the ''Picornaviridae'', they have since been reclassified into their own family. The name (Dicistro) is derived from the characteristic dicistronic arrangement of the genome. This family is a member of the Order ''

'' (along with the families '' Iflaviridae'', ''

Picornaviridae Picornaviruses are a group of related nonenveloped RNA viruses which infect vertebrates including fish, mammals, and birds. They are viruses that represent a large family of small, positive-sense, single-stranded RNA viruses with a 30 nm ...

'', and ''

Secoviridae ''Secoviridae'' is a family of viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bact ...

'' and '' Marnaviridae''). Within this order, the gene order is the gene order of the nonstructural proteins Hel(helicase)-Pro(protease)-RdRp(polymerase). The ''Dicistroviridae'' can be distinguished from the members of the taxa by the location of their structural protein genes at the 3' end rather than the 5' end (as found in ''Iflavirus'', ''Picornaviridae'' and ''Secoviridae'') and by having two genomic segments rather than a single one (as in the ''Comovirus''). The family contains the following genera and species: Genus: '' Aparavirus'' * '' Aparavirus apisacutum'', Acute bee paralysis virus * ''Aparavirus cancerluti'', Mud crab virus * ''Aparavirus israelense'', Israeli acute paralysis virus * ''Aparavirus kashmirense'', Kashmir bee virus * ''Aparavirus tauraense'', Taura syndrome virus * ''Aparavirus vallesi'', Solenopsis invicta virus 1 Genus: '' Cripavirus'' * ''Cripavirus drosophilae'', Drosophila C virus * ''Cripavirus grylli'', Cricket paralysis virus * ''Cripavirus mortiferum'', Aphid lethal paralysis virus * ''Cripavirus porteri'', Solenopsis invicta virus 6 * ''Cripavirus ropadi'', Rhopalosiphum padi virus Genus: '' Triatovirus'' * ''Triatovirus himetobi'', Himetobi P virus * ''Triatovirus hocoagulatae'',

Homalodisca coagulata virus-1 ''Homalodisca''Stål C (1869) ''Hemiptera Fabriciana. Fabricianska Hemipterarter, efter de Köpenhamn och Kiel förvarade typexemplaren granskade och beskrifne. 2. Kongliga Svenska Vetenskaps Akademien Handlingar'' 8(1): 1–130. is a genus of s ...

* ''Triatovirus nigereginacellulae'', Black queen cell virus * ''Triatovirus plastali'', Plautia stali intestine virus * ''Triatovirus triatomae'', Triatoma virus Linepithema humile virus 1 is possibly a member of ''Dicistroviridae'', of unclear placement.

Structure

Viruses in ''Dicistroviridae'' are non-enveloped, with icosahedral geometries, and T=pseudo3 symmetry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 8.5-10.2kb in length. 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.

RNA structural elements

Many of the ''Dicistroviridae'' genomes contains structured RNA elements. For example, the Cripaviruses have an

internal ribosome entry site An internal ribosome entry site, abbreviated IRES, is an RNA element that allows for translation initiation in a cap-independent manner, as part of the greater process of protein synthesis. Initiation of eukaryotic translation nearly always occur ...

, which mimics a Met-

tRNA Transfer ribonucleic acid (tRNA), formerly referred to as soluble ribonucleic acid (sRNA), is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes). In a cell, it provides the physical link between the gene ...

and is used in the

initiation Initiation is a rite of passage marking entrance or acceptance into a group or society. It could also be a formal admission to adulthood in a community or one of its formal components. In an extended sense, it can also signify a transformatio ...

of translation.

References

*Hunter, WB, Katsar, CS, Chaparro, JX. 2006. Molecular analysis of capsid protein of ''Homalodisca coagulata virus-1'', a new leafhopper-infecting virus from the glassy-winged sharpshooter, ''Homalodisca coagulata''
Journal of Insect Science 6:31
*Hunnicutt, LE, Hunter, WB, Cave RD, Powell, CA, Mozoruk, JJ. 2006. Genome sequence and molecular characterization of ''Homalodisca coagulata virus-1'', a novel virus discovered in the glassy-winged sharpshooter (Hemiptera: Cicadellidae)

*Valles, SM, Strong, CA, Dang, PM, Hunter, WB, Pereira, RM, Oi, DH, Shapiro, AM, Williams, DF. 2004. A picorna-like virus from the red imported fire ant, ''Solenopsis invicta'': initial discovery, genome sequence, and characterization
Virology 328: 151–157
*

External links

ICTV Online (10th) Report: ''Dicistroviridae''

Beediseases
Honey bee diseases website by Dr. Guido Cordoni. {{Taxonbar, from=Q3026565 Picornavirales Virus families