Ranavirus
| Ranavirus | |
|---|---|
| |
Transmission electron micrograph of ranaviruses (dark hexagons) gathering at the cell border and leaving the cell via a process called "budding ".
| |
Virus classification 
| |
| (unranked): | Virus |
| Realm: | Varidnaviria |
| Kingdom: | Bamfordvirae |
| Phylum: | Nucleocytoviricota |
| Class: | Megaviricetes |
| Order: | Pimascovirales |
| Family: | Iridoviridae |
| Subfamily: | Alphairidovirinae |
| Genus: | Ranavirus |
Ranavirus is a genus of
Ecological impact
The Ranaviruses, like the Megalocytiviruses, are an
Etymology
Rana is derived from the
Evolution
The ranaviruses appear to have evolved from a fish virus which subsequently infected amphibians and reptiles.[13]
Hosts
Anuran hosts
- Wood frogs (Lithobates sylvaticus)
- American Bullfrog (Lithobates catesbieanus)
- Pickerel Frog
Urodelan hosts
Reptilian hosts
- Green pythons (Chondropython viridis)[14]
- Burmese star tortoises (Geochelone platynota)
- Leopard tortoise (Geochelone pardalis)[15]
- Gopher tortoises (Gopherus polyphemus)
- Mountain lizard (Lacerta monticola)[16]
- Eastern box turtles (Terrapene carolina carolina)[17]
- Florida box turtles (Terrapene carolina bauri)
- Western ornate box turtles (Terrapene ornata)[18]
- Spur-thighed tortoises (Testudo graeca)[19]
- Hermann's tortoises (Testudo hermanni)
- Egyptian tortoises (Testudo kleinmanni)
- Russian tortoises (Testudo horsfieldii)
- Marginated tortoises (Testudo marginata)
- Red-eared sliders (Trachemys scripta elegans)[18]
- Common snapping turtles (Chelydra serpentina)[20]
- Chinese softshell turtles (Pelodiscus sinensis)[21]
- Common flat-tail gecko (Uroplatus fimbriatus)[22]
- Eastern Fence Lizard (Sceloporus undulatus) [23]
Taxonomy
The genus contains the following species:[24]
- Ambystoma tigrinum virus
- Common midwife toad virus
- Epizootic haematopoietic necrosis virus
- European North Atlantic ranavirus
- Frog virus 3
- Santee-Cooper ranavirus
- Singapore grouper iridovirus
The family Iridoviridae is divided into seven genera which include Chloriridovirus, Iridovirus, Lymphocystivirus, Megalocytivirus, and Ranavirus.[1] The genus Ranavirus contains three viruses known to infect amphibians (Ambystoma tigrinum virus (ATV), Bohle iridovirus (BIV), and frog virus 3).[25]
Structure
Ranaviruses are large
| Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
|---|---|---|---|---|---|
| Ranavirus | Polyhedral | T=133 or 147 | Linear | Monopartite |
Replication
Ranaviral replication is well studied using Frog virus 3 (FV3).
| Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
|---|---|---|---|---|---|---|---|
| Ranavirus | Frogs; snakes | None | Cell receptor endocytosis | Lysis; budding | Nucleus | Cytoplasm | Contact |
DNA repair
Transmission
Transmission of ranaviruses is thought to occur by multiple routes, including contaminated soil, direct contact, waterborne exposure, and ingestion of infected tissues during
Ranaviruses are relatively stable in aquatic environments, persisting several weeks or longer outside a host organism.[11]Epizoology
Amphibian mass mortality events due to Ranavirus have been reported in Asia, Europe, North America, and South America.[11] Ranaviruses have been isolated from wild populations of amphibians in Australia, but have not been associated with mass mortality on that continent.[11][33][34]
Pathogenesis
Synthesis of viral proteins begins within hours of viral entry[27] with necrosis or apoptosis occurring as early as a few hours post infection.[26][35]
Seasonal disease dynamics
There are several hypotheses for seasonal outbreak patterns observed for Ranavirosis mortality events.
Environmental persistence
The environmental persistence of Ranaviruses is not understood well, however in realistic environmental conditions the T90 value of an FV3-like virus is 1 day.[40] The duration of persistence is likely affected by temperature and microbial conditions. It is unlikely that ranaviruses persist in the environment outside of host species between outbreak events. Researchers have explored several pathogen reservoirs for the virus which might explain how the virus can persist within an amphibian community. In some amphibian populations, sub-clinically infected individuals may serve as reservoirs for the pathogen.[6] These sub-clinically infected individuals are responsible for reintroduction of the virus to the larval population. With ranaviruses being capable of infected multiple taxa, and with there being differences in susceptibility between taxa, it is likely that sympatric fish and reptile species may serve as reservoirs for virus as well. Interclass transmission has been proven through the use of mesocosm studies.[41]
Gross pathology
Gross lesions associated with Ranavirus infection include erythema, generalized swelling, hemorrhage, limb swelling, and swollen and friable livers.[11]
See also
References
- ^ a b "Iridoviridae". ICTV Online (10th) Report.
- PMID 20050967.
- S2CID 85889833.
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- ^ doi:10.1890/02-0374.
- .
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- ^ Harper, Douglas. "frog". Online Etymology Dictionary.
- S2CID 1534726.
- ^ PMID 20099417.
- S2CID 38763155.
- PMID 20042506.
- S2CID 17427050.
- ^ Benetka V. (2007). "First report of an iridovirus (genus Ranavirus) infection in a leopard tortoise (Geochelone pardalis pardalis)" (PDF). Vet Med Austria. 94: 243–248.
- S2CID 21932480.
- PMID 9123863.
- ^ PMID 17491069.
- ^ Blahak S., Uhlenbrok C. "Ranavirus infections in European terrestrial tortoises in Germany". Proceedings of the 1st International Conference on Reptile and Amphibian Medicine; Munich, Germany. 4–7 March 2010; pp. 17–23
- S2CID 92405818.
- PMID 10509727.
- S2CID 20616080.
- S2CID 91510246.
- ^ "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 22 May 2021.
- ^ a b c Chinchar VG, Essbauer S, He JG, Hyatt A, Miyazaki T, Seligy V, Williams T (2005). "Family Iridoviridae" pp. 145–162 in Fauquet CM, Mayo MA, Maniloff J, Desselburger U, Ball LA (eds). Virus Taxonomy, Eighth report of the International Committee on Taxonomy of Viruses. Academic Press, San Diego, USA.
- ^ a b c Williams T, Barbosa-Solomieu V, Chinchar GD (2005). "A decade of advances in iridovirus research" 173-148. In Maramorosch K, Shatkin A (eds). Advances in virus research, Vol. 65 Academic Press, New York, USA.
- ^ S2CID 24928231.
- PMID 21994690.
- ^ PMID 7109033.
- PMID 34586876.
- ^ Ke F, Zhang QY. ADRV 12L: A Ranaviral Putative Rad2 Family Protein Involved in DNA Recombination and Repair. Viruses. 2022 Apr 27;14(5):908. doi: 10.3390/v14050908. PMID: 35632650; PMCID: PMC9146916
- PMID 24667325.
- .
- PMID 12078986.
- PMID 12642103.
- ^ ISBN 978-3-319-13755-1.
- ^ S2CID 33944909.
- ^ Green, D E; Converse, K A (2005). "Diseases of frogs and toads". Wildlife Diseases: Landscape Epidemiology, Spatial Distribution, and Utilization of Remote Sensing Technology.: 89-117.
- S2CID 27561247.
- PMID 25266900.
- PMID 24667325.
External links
Data related to List of viruses at Wikispecies
- ICTV Online (10th) Report: Iridoviridae
- Viralzone: Ranavirus
- Global Ranavirus Consortium
- Viral Diseases of Amphibians
- More information on Ranavirus and other pathogens impacting amphibian populations, including Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans can be found at the Southeast Partners in Amphibian and Reptile Conservation disease task team web-page. [1]