''Iflaviridae'' is a family of positive sense RNA viruses

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

-infecting

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

es. Some of the insects commonly infected by iflaviruses include

aphid 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 ...

leafhopper Leafhopper is the common name for any species from the family (biology), family Cicadellidae: based on the type genus ''Cicadella''. These minute insects, colloquially known as hoppers, are plant feeders that suck plant sap from grass, shrubs, or ...

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 ...

bee 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 ...

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

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 and

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder ...

s. The name "Ifla" is derived from the name "Infectious flacherie virus", a member species. There is one genus (''Iflavirus'') and 16 species in this family.

Structure

Members of this family are insect-infecting viruses that consist of positive single-strand RNA genomes translated into a single polyprotein of ~3000 amino acids long. It encodes

helicase Helicases are a class of enzymes that are vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic double helix, separating the two hybridized ...

protease A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products ...

and

RNA-dependent RNA polymerase RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the self-replication, replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand Complementarity (molecular biology), compleme ...

enzymes and four structural proteins (VP1–4). The non-enveloped

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 m ...

has an

icosahedral In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes . The plural can be either "icosahedra" () or "icosahedrons". There are infinitely many non- similar shapes of icosahedra, some of them being more symmetrical tha ...

T=pseudo3 symmetry and is around 30 nm in diameter. VP1, VP2 and VP3 form the outer portion, with VP4 located internally. Genomes are linear and non-segmented, around 8.8-9.7kb in length.

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Translation takes place by ribosomal skipping. Insects serve as the natural host.

Pathogenicity

Several viruses in this family are economically important because they are highly pathogenic to their honeybee and silkworm hosts, while others (including Dinocampus coccinellae paralysis virus, Nasonia vitripennis virus and Venturia canescens picorna-like virus) appear to cause little or no symptoms.

Taxonomy

The family ''Iflaviridae'' contains one genus, ''Iflavirus'', with the following 16 species, listed by scientific name and followed by the exemplar virus of the species: * ''Iflavirus achedomestici'',

Acheta domesticus iflavirus ''Acheta'' is a genus of crickets. It most notably contains the house cricket (''Acheta domesticus''). According to Direction 46 issued by the ICZN in 1956, this generic name is masculine in gender.Deformed wing virus * ''Iflavirus apistardum'', Slow bee paralysis virus * ''Iflavirus betaspexiguae'',

Spodoptera exigua iflavirus 2 ''Spodoptera'' is a genus of moths of the family Noctuidae erected by Achille Guenée in 1852. Many are known as pest insects. The larvae are sometimes called armyworms. The roughly thirty species are distributed across six continents. Descrip ...

* ''Iflavirus brebrassicae'',

Brevicoryne brassicae virus ''Brevicoryne'' is a genus of aphid insect that contains many species which are agricultural pests. Hosts This genus parasitizes a wide range of hosts, with many members of the Brassicaceae (broccoli, cabbage, kale, etc.) included. Adults Adul ...

* ''Iflavirus dinococcinellae'',

Dinocampus coccinellae paralysis virus Dinocampus coccinellae paralysis virus (DcPV) is a single-stranded, positive-sense RNA virus of insects, in the Picornavirales, picorna-like virus family ''Iflaviridae'', which was first characterised in 2015. It asymptomatically infects the para ...

* ''Iflavirus ectobliquae'', Ectropis obliqua virus * ''Iflavirus flacherie'',

Infectious flacherie virus infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disea ...

* ''Iflavirus lineacelli'',

Lymantria dispar iflavirus 1 ''Lymantria'' is a genus of tussock moths in the family Erebidae. They are widely distributed throughout Europe, Japan, India, Sri Lanka, Myanmar, Java, and Celebes. The genus was erected by Jacob Hübner in 1819. Description In the male, the pa ...

* ''Iflavirus lylineolaris'',

Lygus lineolaris virus 1 The genus ''Lygus'' includes over 40 species of plant-feeding insects in the family Miridae. The term lygus bug is used for any member of genus ''Lygus''. Species At one time, nearly 200 species were classified as genus ''Lygus'', but most of th ...

* ''Iflavirus nilalugentis'',

Nilaparvata lugens honeydew virus 1 ''Nilaparvata''Distant WL (1906) ''The fauna of British India, including Ceylon and Burma.'' 3: 503 pp. 47 is a genus of planthoppers in the subfamily Delphacinae and tribe Delphacini Leach, 1815. Species are widely distributed in the Americas, ...

* ''Iflavirus pernudae'', Perina nuda virus * ''Iflavirus sacbroodi'',

Sacbrood virus Sacbrood virus or SBV disease is an infectious disease caused by the ''Morator aetatulas'' virus, which affects honey bee larvae. When infected, the colony declines gradually with few or no replacement workers, resulting in a loss of 20-80% of ho ...

* ''Iflavirus spexiguae'',

Spodoptera exigua iflavirus 1 ''Spodoptera'' is a genus of moths of the family Noctuidae erected by Achille Guenée in 1852. Many are known as pest insects. The larvae are sometimes called armyworms. The roughly thirty species are distributed across six continents. Descrip ...

* ''Iflavirus vadestruente'', Varroa destructor iflavirus 1 * ''Iflavirus vomitus'',

Antheraea pernyi iflavirus ''Antheraea'' is a genus of moths belonging to the family Saturniidae. It was erected by Jacob Hübner in 1819. Several species of this genus have caterpillars which produce wild silk of commercial importance. Commonly called "tussar silk", the ...

References

External links

ICTV Online (10th) Report; Iflaviridae

ICTV Online (10th) Report; Iflaviridae, alternative link

{{Taxonbar, from=Q5991208 Picornavirales Virus families