''Proboscivirus'' is a genus of
virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsk ...
es in the order ''
Herpesvirales
The ''Herpesvirales'' is an order of dsDNA viruses (Baltimore group I) with animal hosts, characterised by a common morphology consisting of an icosahedral capsid enclosed in a glycoprotein-containing lipid envelope. Common infections in humans ...
'', in the family ''
Herpesviridae
''Herpesviridae'' is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ''ἕρπει ...
'', in the subfamily ''
Betaherpesvirinae
''Betaherpesvirinae'' is a subfamily of viruses in the order ''Herpesvirales'' and in the family ''Herpesviridae''. Mammals serve as natural hosts. There are 26 species in this subfamily, divided among 5 genera. Diseases associated with this sub ...
''.
Elephant
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae ...
s serve as natural hosts.
EEHV1 is apathogenic for
African elephants but causes fatal haemorrhagic disease in
Asian elephant
The Asian elephant (''Elephas maximus''), also known as the Asiatic elephant, is the only living species of the genus ''Elephas'' and is distributed throughout the Indian subcontinent and Southeast Asia, from India in the west, Nepal in the no ...
s.
The name "''Proboscivirus''" comes from the Greek word or "
proboscis
A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elong ...
" meaning "the
elephant trunk," for which the virus accordingly uses as its means of contraction and transmission (secretions or openings of the trunk) 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'' (Acronym: EEHV1 and Scientific Name:
Elephant endotheliotropic herpesvirus) under ICTV §2005.051-050V.04.
It was suggested by Pellett (2014) 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:
* ''
Elephantid betaherpesvirus 1''
* ''
Elephantid betaherpesvirus 4''
* ''
Elephantid betaherpesvirus 5''
Structure
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
ixtureand 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 (or trunk for Elephants) on its host - often leading to death afterwards.
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.
References
External links
Viralzone: ''Proboscivirus''ICTV
{{Taxonbar, from=Q16988512
Betaherpesvirinae
Virus genera