Biology:Cyprinid herpesvirus 2

From HandWiki
Short description: Species of virus


Cyprinid herpesvirus 2
Virus classification e
Missing taxonomy template (fix): Cyvirus
Species:
Cyvirus cyprinidallo2
Synonyms
  • Cyprinid herpesvirus 2
  • CyHV2

Cyprinid herpesvirus 2 (CyHV2) is a species of virus in the genus Cyvirus, family Alloherpesviridae, and order Herpesvirales.[1][2]

CyHV2 can also be classified as herpesviral hematopoietic necrosis virus (HVHN) and infects goldfish (Carassius auratus) of all ages.[3][4] It can also infect the closely related species, Prussian Carp (C. gibelio) however koi and goldfish hybrids cannot be infected by CyHV2.[3] Outbreaks have been reported in both cultured and wild populations, and are highly lethal.[3]

Background

Jung and Miyazaki (1995) were the first to describe CyHV2 in Japan.[3][5] This was achieved via isolation from moribund goldfish after the epizootic disease was observed in 1992 and 1993.[5] Culture of HVHN was unsuccessful until 2007.[6]

Genome

Whole genome sequencing revealed that the CyHV2 genome is 290,304 bp in size.[4] This number may be variable due to tandem reiterations.[4] Heterogeneous genome size is often observed in other species of herpesviruses.[4] These short yet complex tandem reiterations are most often seen in the terminal direct repeats; the most prevalent being the telomere-like repeats located towards the genome ends.[4] In comparison to the other viruses, the CyHV2 genome is the most complex in terms of the unique regions plus one copy of terminal direct repeats.[4]

HVHN has approximately 154 open reading frames (ORFs) and splicing between protein-coding regions affects 9 of these ORFs.[4] Five gene families have been identified. This included multiple genes from TNFR, ORF2, ORF25, RING, and ORF153, as well as ORF22, which is present as a family of two.[4]

Pathology

External symptoms of fish impacted with CyHV2 typically show pale patches localized at the gills but do not exhibit lesions.[3][6] Fish with this infection also appeared to be lethargic, anorexic, and exhibited a loss of appetite.[3][6] CyHV2 is more often characterized by internal symptoms such as an enlarged kidney and spleen, as well as pallor of the kidney.[3] Histopathology of infected goldfish has revealed tissue death in the hematopoietic tissues in both the kidney and the splenic pulp.[3] Necrosis was also observed in the pancreas.[3][5] Smaller, more scattered tissue death and swelling was also observed in the lamina propria as well as the submucosa of the intestine.[3][5]

At this time, disease prevention is mainly achieved by avoidance.[3] A formalin-inactivated vaccine developed in 2015 was effective against goldfish infected with HVHN, however, as of now, there is not an established timeline that discusses the duration of protection.[3][7]

References

  1. ↑ "Taxon Details: Cyvirus cyprinidallo2". International Committee on Taxonomy of Viruses. https://ictv.global/taxonomy/taxondetails?taxnode_id=202501401&taxon_name=Cyvirus%20cyprinidallo2. 
  2. ↑ "Family: Alloherpesviridae (Interim Report)". International Committee on Taxonomy of Viruses. https://ictv.global/report/chapter/alloherpesviridae/alloherpesviridae. 
  3. ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 Hanson, L.; Doszpoly, A.; van Beurden, S. J.; de Oliveira Viadanna, P. H.; Waltzek, T. (2016). "Alloherpesviruses of Fish" (in en). Aquaculture Virology. Elsevier. pp. 153–172. doi:10.1016/b978-0-12-801573-5.00009-7. ISBN 978-0-12-801573-5. https://linkinghub.elsevier.com/retrieve/pii/B9780128015735000097. Retrieved 2024-03-27. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 Davison, A. J.; Kurobe, T.; Gatherer, D.; Cunningham, C.; Korf, I.; Fukuda, H.; Hedrick, R. P.; Waltzek, T. B. (2013). "Comparative Genomics of Carp Herpesviruses" (in en). Journal of Virology 87 (5): 2908–2922. doi:10.1128/JVI.03206-12. ISSN 0022-538X. PMID 23269803. 
  5. ↑ 5.0 5.1 5.2 5.3 Jung, S. J.; Miyazaki, T. (1995). "Herpesviral haematopoietic necrosis of goldfish, Carassius auratus (L.)" (in en). Journal of Fish Diseases 18 (3): 211–220. doi:10.1111/j.1365-2761.1995.tb00296.x. ISSN 0140-7775. Bibcode: 1995JFDis..18..211J. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2761.1995.tb00296.x. 
  6. ↑ 6.0 6.1 6.2 Jeffery, K. R.; Bateman, K.; Bayley, A.; Feist, S. W.; Hulland, J.; Longshaw, C.; Stone, D.; Woolford, G. et al. (2007). "Isolation of a cyprinid herpesvirus 2 from goldfish, Carassius auratus (L.), in the UK" (in en). Journal of Fish Diseases 30 (11): 649–656. doi:10.1111/j.1365-2761.2007.00847.x. ISSN 0140-7775. PMID 17958608. Bibcode: 2007JFDis..30..649J. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2761.2007.00847.x. 
  7. ↑ Ito, T.; Maeno, Y. (2015). "Effect of booster shot and investigation of vaccination efficacy period against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus" (in en). Veterinary Microbiology 175 (1): 139–144. doi:10.1016/j.vetmic.2014.11.005. PMID 25434995. https://linkinghub.elsevier.com/retrieve/pii/S0378113514005173. 
  • Data related to Cyprinid herpesvirus 2 at Wikispecies

Wikidata ☰ Q18965129 entry



Retrieved from "https://handwiki.org/wiki/index.php?title=Biology:Cyprinid_herpesvirus_2&oldid=4522409"