Proboscivirus


Proboscivirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Betaherpesvirinae. Elephants serve as natural hosts. EEHV1 causes asymptomatic infection in African elephants but causes fatal haemorrhagic disease in Asian elephants. The name "Proboscivirus" comes from the Greek word προβοσκίς or "proboscis" meaning "the elephant trunk," for which the virus accordingly uses as a means of contraction and transmission to enter the elephant's body.

Taxonomy

Proboscivirus is located under the listings of the ICTV Updates as Section §2005.049-050V.04. With the creation of Proboscivirus as a new genus came the creation and categorization of a new species under this genus, by the name of Elephantid betaherpesvirus 1 under ICTV §2005.051-050V.04.
It was suggested by Pellett that the phylogenetic divergence of Proboscivirus from other genera in the subfamily Betaherpesvirinae warrants reassignment of the genus to a new subfamily that would be called Deltaherpesvirinae. However, the genus remains in the Betaherpesvirinae in currently accepted ICTV taxonomy.

Species

The genus consists of the following species:
Viruses in Proboscivirus are enveloped, with icosahedral, spherical to pleomorphic, and round geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented.
Considering Proboscivirus is a herpesvirus, it is then unique in the sense that morphologically the virus is atypical to other viruses. According to University of Glasgow Immunology & Virology Professor, A.J. Davison, and his research team, the Proboscivirus morphology is a "linear, double-stranded DNA genome of 125-290 kbp contained within a T=16 icosahedral capsid, which is surrounded by proteinaceous and lipid envelope containing membrane-associated proteins". Species under the genus Proboscivirus tend to leave physical symptoms of cyanosis of the tongue, mouth/stomach ulcers, oedema of the head on its host - often leading to death afterwards.
GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
ProboscivirusSpherical PleomorphicT=16EnvelopedLinearMonopartite

Life cycle

Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of the viral glycoproteins to host receptors, which mediates endocytosis. Replication follows the dsDNA bidirectional replication model. DNA-templated transcription, with some alternative splicing mechanism is the method of transcription. The virus exits the host cell by nuclear egress, and budding.
Elephants serve as the natural host.
GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
ProboscivirusElephants-GlycoprotiensBuddingNucleusNucleusContact