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 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 Picornavirales (along with the families Iflaviridae, Picornaviridae, and Secoviridae 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 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.
Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentationAparavirusIcosahedralPseudo T=3Non-envelopedLinearCripavirusIcosahedralPseudo T=3Non-envelopedLinearMonopartite
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.
Genus Host details Tissue tropism Entry details Release details Replication site Assembly site TransmissionAparavirusInvertebrates: honeybee, bumblebeesNoneUnknownUnknownCytoplasmCytoplasmUnknownCripavirusInvertebratesNoneCell receptor endocytosisBuddingCytoplasmCytoplasmFood
RNA structural elements Many of the Dicistroviridae genomes contains structured RNA elements. For example, the Cripaviruses have an internal ribosome entry site, which mimics a Met-tRNA and is used in the initiation 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). Virology 350: 67–78 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 Viralzone: Dicistroviridae Beediseases Honey bee diseases website by Dr. Guido Cordoni.