Bracovirus

Last updated

Bracovirus
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Viriform
Family: Polydnaviriformidae
Genus:Bracoviriform
Synonyms

Bracoviriform

  • BracoviriformICTV 2021
  • BracovirusICTV 1990
  • PolydnavirusICTV 1984

Bracovirus is a genus of viruses, in the family Polydnaviridae . Bracoviruses are an ancient symbiotic virus contained in parasitic braconid wasps that evolved from the nudivirus approximately 190 million years ago and has been evolving for at least 100 million years. [1] It is one of two genera belonging to the Polydnaviridae family, with Ichnovirus being the other genus. There are 32 species in this genus. [2] [3]

Contents

Symbiosis

Parasitoid wasps in the subfamilies Microgastrinae, Miracinae, Cheloninae, Cardiochilinae, Khoikhoiinae, and Mendesellinae are the natural hosts for Bracoviruses, though the virus does not cause disease in these wasps. Instead, the wasps are themselves parasites of lepidoptera. The wasp injects one or more eggs into its lepidoptera host along with a quantity of virus. The virus does not replicate inside the wasp's host, but expression of viral genes prevents its immune system from killing the wasp's egg and causes other physiological alterations that ultimately cause the parasitized host to die. [2] Studies conducted on Cotesia congregata have shown that male wasps do contain proviral sequences of DNA, but the females are the ones responsible for the amplification of the viral DNA. [4]

Taxonomy

The genus Bracovirus contained the 32 species in ICTV versions 1999a-2020 [5] The genus Bracoviriform contains the following 31 species starting ICTV version 2021 [3] The species Ichnoviriform rostralis, previously known as Tranosema rostrale bracovirus was moved to Ichnoviriform (Ichnovirus) from Bracoviriform (Bracovirus) in 2021.

SpeciesPrevious name,
Virus name
Abbreviation
Bracoviriform altitudinisChelonus altitudinis bracovirusCalBV
Bracoviriform argentifrontisAscogaster argentifrons bracovirusAaBV
Bracoviriform blackburniChelonus blackburni bracovirusCbBV
Bracoviriform canadenseHypomicrogaster canadensis bracovirusHcBV
Bracoviriform congregataeCotesia congregata bracovirusCcBV
Bracoviriform crassicornisApanteles crassicornis bracovirusAcBV
Bracoviriform croceipedisMicroplitis croceipes bracovirusMcBV
Bracoviriform curvimaculatiChelonus nr. curvimaculatus bracovirusCcBV
Bracoviriform demolitorisMicroplitis demolitor bracovirusMdBV
Bracoviriform ectdytolophaeHypomicrogaster ectdytolophae bracovirusHcEV
Bracoviriform facetosaeDiolcogaster facetosa bracovirusDfBV
Bracoviriform flavicoxisGlyptapanteles flavicoxis bracovirusGflBV
Bracoviriform flavipedisCotesia flavipes bracovirusCfBV
Bracoviriform flavitestaceaePhanerotoma flavitestacea bracovirusPfBV
Bracoviriform fumiferanaeApanteles fumiferanae bracovirusAfBV
Bracoviriform glomerataeCotesia glomerata bracovirusCgBV
Bracoviriform hyphantriaeCotesia hyphantriae bracovirusChBV
Bracoviriform inanitiChelonus inanitus bracovirusCinaBV
Bracoviriform indienseGlyptapanteles indiensis bracovirusGiBV
Bracoviriform insularisChelonus insularis bracovirusCinsBV
Bracoviriform kariyaiCotesia kariyai bracovirusCkBV
Bracoviriform liparidisGlyptapanteles liparidis bracovirusGlBV
Bracoviriform marginiventrisCotesia marginiventris bracovirusCmaBV
Bracoviriform melanoscelaeCotesia melanoscela bracovirusCmeBV
Bracoviriform nigricipitisCardiochiles nigriceps bracovirusCnBV
Bracoviriform ornigisPholetesor ornigis bracovirusPoBV
Bracoviriform paleacritaeProtapanteles paleacritae bracovirusPpBV
Bracoviriform quadridentataeAscogaster quadridentata bracovirusAqBV
Bracoviriform rubeculaeCotesia rubecula bracovirusCrBV
Bracoviriform schaeferiCotesia schaeferi bracovirusCsBV
Bracoviriform texaniChelonus texanus bracovirusCtBV

Structure

Viruses in Bracovirus are enveloped, with prolate ellipsoid and cylindrical geometries. Genomes are circular and segmented, around 2.0-31kb in length. The genome of the virus is enveloped with 35 double stranded DNA (dsDNA) all of which are circular. [2] [4]

GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
BracovirusProlate ellipsoidEnvelopedCircularSegmented

Life cycle

Viral replication is nuclear. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export. Transmission routes are parental. [2]

The replication of the Bracoviriform occurs within the ovaries of a parasitic wasps in calyx cells and is maintained by vertical transmission and to go into further detail the packaged genome of dsDNA is replicated inside of the wasp ovaries by development of the sequences of the virus from proviral segments in the tandem arrays in the wasp genome. The development of the sequences of Bracoviriform shows head-to-head and tail-to-tail sequences, which is unexpected, given that it has evolved from the nudivirus [4] The research conducted on Cotesia congregata shows that the viral genome contains one to three proviral segments. [4]

The virus like particle is transmitted into a lepidopteran host (a caterpillar) and infects and manipulates the physiology of the caterpillar so that it can be used as a living incubator for wasp larvae. When this happens the virus disrupts the caterpillar's immune system causing paralysis and inhibiting the pupating of the host. The arresting of the host increases the chance of success of the wasp larva developing successfully. [1]

GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
BracoviriformParasitoid wasps (Braconidae)Hemocytes; fat bodiesUnknownLysis; buddingNucleusNucleusUnknown

[2]

Related Research Articles

<i>Flaviviridae</i> Family of viruses

Flaviviridae is a family of enveloped positive-strand RNA viruses which mainly infect mammals and birds. They are primarily spread through arthropod vectors. The family gets its name from the yellow fever virus; flavus is Latin for "yellow", and yellow fever in turn was named because of its propensity to cause jaundice in victims. There are 89 species in the family divided among four genera. Diseases associated with the group include: hepatitis (hepaciviruses), hemorrhagic syndromes, fatal mucosal disease (pestiviruses), hemorrhagic fever, encephalitis, and the birth defect microcephaly (flaviviruses).

<i>Hepadnaviridae</i> Family of viruses

Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.

Rhadinovirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Gammaherpesvirinae. Humans and other mammals serve as natural hosts. There are 12 species in this genus. Diseases associated with this genus include: Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease, caused by Human gammaherpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV). The term rhadino comes from the Latin fragile, referring to the tendency of the viral genome to break apart when it is isolated.

<i>Polydnaviriformidae</i> Family of viruses

Polydnaviriformidae ( PDV) is a family of insect viriforms; members are known as polydnaviruses. There are two genera in the family: Bracoform and Ichnoviriform. Polydnaviruses form a symbiotic relationship with parasitoid wasps. Ichnoviriforms (IV) occur in Ichneumonid wasps and Bracoviriforms (BV) in Braconid wasps. The larvae of wasps in both of those groups are themselves parasitic on Lepidoptera, and the polydnaviruses are important in circumventing the immune response of their parasitized hosts. Little or no sequence homology exists between BV and IV, suggesting that the two genera have been evolving independently for a long time.

<i>Mardivirus</i> Genus of viruses in the family Herpesviridae affecting Chickens, turkeys, and quail

Mardivirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Alphaherpesvirinae. Chickens, turkeys, and quail serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: Marek's disease, which causes asymmetric paralysis of one or more limbs, neurological symptoms, and development of multiple lymphomas that manifest as solid tumors. Gallid herpesvirus 2 is the only one of these viruses known to be pathogenic and due to the antigenic similarity between the three viruses the other two have been used to vaccinate against Marek's disease. These viruses have double stranded DNA genomes with no RNA intermediate.

<span class="mw-page-title-main">Braconidae</span> Family of wasps

The Braconidae are a family of parasitoid wasps. After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed. One analysis estimated a total between 30,000 and 50,000, and another provided a narrower estimate between 42,000 and 43,000 species.

<span class="mw-page-title-main">Parasitoid wasp</span> Group of wasps

Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps (Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later causing the death of these hosts. Different species specialise in hosts from different insect orders, most often Lepidoptera, though some select beetles, flies, or bugs; the spider wasps (Pompilidae) exclusively attack spiders.

Petuvirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There is only one species in this genus: Petunia vein clearing virus. Diseases associated with this genus include: plants: chlorotic vein clearing, leaf malformation.

<i>Cotesia congregata</i> Species of wasp

Cotesia congregata is a parasitoid wasp of the genus Cotesia. The genus is particularly noted for its use of polydnaviruses. Parasitoids are distinct from true parasites in that a parasitoid will ultimately kill its host or otherwise sterilize it.

<i>Ascoviridae</i> Family of viruses

Ascoviridae is a family of double strand DNA viruses that infect primarily invertebrates, mainly noctuids and spodoptera species; it contains two genera, Ascovirus, which contains three species, and Toursvirus with a single species Diadromus pulchellus toursvirus.

<span class="mw-page-title-main">Microgastrinae</span> Subfamily of wasps

Microgastrinae is a subfamily of braconid wasps, encompassing almost 3,000 described species, with an estimated 30,000–50,000 total species. This makes it one of the richest subfamilies with the most species of parasitoid wasps.

<span class="mw-page-title-main">Nudivirus</span> Family of viruses

Nudiviruses are a genus of anthropod viruses that constitute the family Nudiviridae. Insects and marine crustaceans serve as natural hosts to this family of viruses. Nudiviruses are double-stranded DNA viruses, with their genome notably ranging from 130-140 kilobases in length. There are 20 species in this family, assigned to 4 genera. Diseases associated with this family include: death in larvae, and chronic disease in adults.

<span class="mw-page-title-main">Iflaviridae</span> Family of viruses

Iflaviridae is a family of positive sense RNA viruses insect-infecting viruses. Some of the insects commonly infected by iflaviruses include aphids, leafhoppers, flies, bees, ants, silkworms and wasps. 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.

Babuvirus is a genus of viruses, in the family Nanoviridae. Musa species serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: stunting, severe necrosis and early plant death. BBTV induces banana bunchy top disease (BBTD).

Cavemovirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are three species in this genus. Diseases associated with this genus include: vein-clearing or banding mosaic.

Ichnovirus is a genus of viruses, in the family Polydnaviridae. Parasitoid wasps serve as hosts, and these wasps are themselves parasitoids of Lepidoptera. There are 21 species in this genus.

Percavirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Gammaherpesvirinae. Mammals serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: conjunctivitis, immunosuppression in foals, pneumonia, respiratory disease.

Aurivirus is a genus of viruses in the order Herpesvirales, and one of only two genera the family Malacoherpesviridae. Haliotid molluscs serve as natural hosts. There is only one species described in this genus, Haliotid herpesvirus 1 (AbHV-1), commonly known as abalone herpesvirus. A disease associated with this virus is acute ganglioneuritis.

Solendovirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are two species in this genus. Diseases associated with this genus include: TVCV: vein-clearing symptoms in N. edwardsonii.

<i>Trichomonasvirus</i> Genus of viruses

Trichomonasvirus is a genus of viruses, in the family Totiviridae. The protozoan parasite Trichomonas vaginalis serves as the natural host. There are four species in this genus.

References

  1. 1 2 "Oldest Viruses Infected Insects 300 Million Years Ago". Live Science . 12 September 2011.
  2. 1 2 3 4 5 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  3. 1 2 "Virus Taxonomy: 2022 Release". International Committee on Taxonomy of Viruses (ICTV). March 2023. Retrieved 15 August 2023.
  4. 1 2 3 4 Louis, F.; Bezier, A.; Periquet, G.; Ferras, C.; Drezen, J.-M.; Dupuy, C. (2013). "The Bracovirus Genome of the Parasitoid Wasp Cotesia congregata is Amplified within 13 Replication Units, Including Sequences Not Packaged in the Particles" (PDF). Journal of Virology. 87 (17): 9649–9660. doi:10.1128/JVI.00886-13. PMC   3754133 . PMID   23804644.
  5. "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2020. Retrieved 15 August 2023.