View source for Cytomegalovirus

{{Infobox disease 
|  Name        = Cytomegalovirus
|  ICD10       = {{ICD10|B|25||b|25}} 
|  ICD9        = {{ICD9|078.5}} 
|  MedlinePlus = 000568
|  MeshID      = D003586
}}
{{Taxobox
| color              = violet
| name               = ''Cytomegalovirus''
| image              = Cytomegalovirus 01.jpg
| image_caption      = Typical "owl eye" [[Inclusion bodies|inclusion]] indicating CMV infection of a lung [[pneumocyte]]<ref>{{cite journal |author=Mattes FM, McLaughlin JE, Emery VC, Clark DA, Griffiths PD |title=Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7 |journal=J. Clin. Pathol. |volume=53 |issue=8 |pages=612–4 |date=August 2000 |pmid=11002765 |pmc=1762915 |doi= 10.1136/jcp.53.8.612|url=}}</ref>
| virus_group        = i
| ordo               = ''[[Herpesvirales]]''
| familia            = ''[[Herpesviridae]]''
| subfamilia         = ''[[Betaherpesvirinae]]''
| genus              = '''''Cytomegalovirus'''''
| type_species       = ''[[Human cytomegalovirus]]'' }}
{{main|Human cytomegalovirus}}
'''''Cytomegalovirus''''' (from the [[Ancient Greek|Greek]] ''cyto-'', "cell", and ''megalo-'', "large") is a genus of [[viruses]] in the order [[Herpesvirales]], in the family [[Herpesviridae]], in the subfamily [[Betaherpesvirinae]]. Human and  monkeys serve as natural hosts. There are currently eight species in this genus including the type species [[human herpesvirus 5]]. Diseases associated with  HHV-5 include [[infectious mononucleosis|mononucleosis]], and [[pneumonia]]s.<ref name=ViralZone>{{cite web|title=Viral Zone|url=http://viralzone.expasy.org/all_by_species/180.html|publisher=ExPASy|accessdate=15 June 2015}}</ref><ref name=ICTV>{{cite web|last1=ICTV|title=Virus Taxonomy: 2014 Release|url=http://ictvonline.org/virusTaxonomy.asp|accessdate=15 June 2015}}</ref> It is typically abbreviated as CMV.

The [[species]] that infects humans is commonly known as [[HCMV (human cytomegalovirus)|human CMV (HCMV)]] or human herpesvirus-5 (HHV-5), and is the most studied of all cytomegaloviruses.<ref name=Sherris>{{cite book | author = Ryan KJ, Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th | pages = 556; 566–9 | publisher = McGraw Hill | year = 2004 | isbn = 0-8385-8529-9 }}</ref> Within ''[[Herpesviridae]]'', CMV belongs to the ''[[Betaherpesvirinae]]'' subfamily, which also includes the genera ''[[Muromegalovirus]]'' and ''[[Roseolovirus|Roseolovirus (HHV-6 and HHV-7)]]''.<ref name="isbn0-521-82714-0">{{cite book |author=Koichi Yamanishi; Arvin, Ann M.; Gabriella Campadelli-Fiume; Edward Mocarski; Moore, Patrick; Roizman, Bernard; Whitley, Richard |title=Human herpesviruses: biology, therapy, and immunoprophylaxis |publisher=Cambridge University Press |location=Cambridge, UK |year=2007 |pages= |isbn=0-521-82714-0 |oclc= |doi= |accessdate=}}</ref> It is related to other herpesviruses within the subfamilies of ''[[Alphaherpesvirinae]]'' that includes [[herpes simplex virus|herpes simplex viruses (HSV)-1 and -2]] and [[varicella-zoster virus]] (VZV), and the ''[[Gammaherpesvirinae]]'' subfamily that includes [[Epstein–Barr virus]].<ref name="Sherris" />

All herpesviruses share a characteristic ability to remain [[Virus latency|latent]] within the body over long periods. Although they may be found throughout the body, CMV infections are frequently associated with the [[salivary gland]]s in humans and other [[mammal]]s.<ref name="isbn0-521-82714-0"/> Other CMV viruses are found in several [[mammal]] species, but [[species]] isolated from animals differ from HCMV in terms of genomic structure, and have not been reported to cause human disease.

==Taxonomy==
<big>'''Group: dsDNA'''</big>
{{Collapsible list|title= <big>Order: [[Herpesvirales]]</big>
|1={{Collapsible list| framestyle=border:none; padding:1.0em;|title=Family: [[Herpesviridae]]
|1={{Collapsible list| framestyle=border:none; padding:1.0em;|title=Sub-Family: [[Betaherpesvirinae]]
|1={{hidden begin|title=<small>Genus: Cytomegalovirus</small>}}
*<small>[[Aotine herpesvirus 1]]</small>
*<small>[[Cebine herpesvirus 1]]</small>
*<small>[[Cercopithecine herpesvirus 5]]</small>
*<small>'''''[[Human herpesvirus 5]]'''''</small>
*<small>[[Macacine herpesvirus 3]]</small>
*<small>[[Panine herpesvirus 2]]</small>
*<small>[[Papiine herpesvirus 3]]</small>
*<small>[[Saimiriine herpesvirus 4]]</small>
{{hidden end}}
}}
}}
}}<ref name=ICTV />

===Species===
{| class = "wikitable" style = "float:right; font-size:85%; margin-left:15px; width:550px"
|+'''''Classified Cytomegaloviruses'''''
! Scientific Name !! Host !! Common Name
|-
|
''[[Human herpesvirus 5]]'' ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=10359 HHV-5])
<br/>''[[Cercopithecine herpesvirus 5]]'' ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=50292 CeHV-5])
<br/>''[[Cercopithecine herpesvirus 8]]'' ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=47929 CeHV-8])
<br/>''[[Panine herpesvirus 2]]'' ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=188763 PoHV-2]) <br/>''[[Pongine herpesvirus 4]]'' (PoHV-4)
<br/>''[[Aotine herpesvirus 1]]'' ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=50290 AoHV-1])—tentative classification
<br/>''[[Aotine herpesvirus 3]]'' (AoHV-3)—tentative classification

|
[[Human]]
<br/>[[African green monkey]]
<br/>[[Rhesus monkey]]
<br/>[[Chimpanzee]] <br/>[[Orangutan]]
<br/>[[Night monkey]]
<br/>"

|
Human CMV (HCMV)
<br/>Simian CMV (SCCMV)
<br/>Rhesus CMV (RhCMV)
<br/>Chimpanzee CMV (CCMV)<br/>"
<br/>Herpesvirus aotus 1
<br/>Herpesvirus aotus 3

|}
Several species of ''Cytomegalovirus'' have been identified and classified for different [[mammal]]s.<ref name="isbn0-521-82714-0"/> The most studied is ''Human cytomegalovirus'' (HCMV), which is also known as ''Human herpesvirus 5'' (HHV-5). Other primate CMV species include ''Chimpanzee cytomegalovirus'' (CCMV) that infects [[chimpanzee]]s and [[orangutan]]s, and ''Simian cytomegalovirus'' (SCCMV) and ''Rhesus cytomegalovirus'' (RhCMV) that infect [[macaque]]s; CCMV is known as both [http://www.uniprot.org/taxonomy/188763 ''Panine herpesvirus 2'' (PaHV-2) and ''Pongine herpesvirus-4'' (PoHV-4)]. SCCMV is called [http://www.uniprot.org/taxonomy/50292 ''Cercopithecine herpesvirus-5'' (CeHV-5)] and RhCMV,  [http://www.uniprot.org/taxonomy/47929 ''Cercopithecine herpesvirus 8'' (CeHV-8)]. A further two viruses found in the [[night monkey]] are tentatively placed in the ''Cytomegalovirus'' genus, and are called ''Herpesvirus aotus 1'' and ''Herpesvirus aotus 3''.  Rodents also have viruses previously called cytomegaloviruses that are now reclassified under the genus ''[[Muromegalovirus]]''; this genus contains ''Mouse cytomegalovirus'' (MCMV) is also known as [http://www.ncbi.nlm.nih.gov/nuccore/NC_004065 ''Murid herpesvirus 1'' (MuHV-1)] and the closely related ''Murid herpesvirus 2'' (MuHV-2) that is found in [[rat]]s. In addition, there many other [[viral species]] with the name ''Cytomegalovirus'' identified in distinct mammals that are as yet [http://www.uniprot.org/taxonomy/342596 not completely classified]; these were predominantly isolated from [[primate]]s and [[rodent]]s.

==Structure==
Viruses in Cytomegalovirus are enveloped, with icosahedral, Spherical to pleomorphic, and  Round geometries, and T=16 symmetry. The diameter is around 150-200&nbsp;nm. Genomes are linear and non-segmented, around 200kb in length.<ref name=ViralZone />

{| class="wikitable sortable" style="text-align:center"
|-
! Genus !! Structure || Symmetry !! Capsid !! Genomic Arrangement !! Genomic Segmentation
|-
|Cytomegalovirus||Spherical Pleomorphic||T=16||Enveloped||Linear||Monopartite
|}

==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. Translation takes place by leaky scanning. The virus exits the host cell by nuclear egress, and  budding.
Human and  monkeys serve as the natural host. Transmission routes are contact, urine, and saliva.<ref name=ViralZone />

{| class="wikitable sortable" style="text-align:center"
|-
! Genus !! Host Details !! Tissue Tropism !! Entry Details !! Release Details !! Replication Site !! Assembly Site !! Transmission
|-
|Cytomegalovirus||Humans; monkeys||Epithelial mucosa||Glycoprotiens||Budding||Nucleus||Nucleus||Urine; saliva
|}

==Genetic engineering==
The CMV promoter is commonly included in [[Vector (molecular biology)|vectors]] used in [[genetic engineering]] work conducted in mammalian cells, as it is a strong promoter and drives constitutive expression of genes under its control.<ref>Kendall Morgan for Addgene Blog. Apr 3, 2014 [http://blog.addgene.org/plasmids-101-the-promoter-region Plasmids 101: The Promoter Region – Let's Go!]</ref>

==References==
{{Reflist|2}}

==External links==
* [http://viralzone.expasy.org/all_by_species/180.html '''Viralzone''': Cytomegalovirus]
* [http://ictvonline.org/virusTaxonomy.asp '''ICTV''']
{{Baltimore classification}}
{{Viral diseases}}
{{Diseases of maternal transmission}}

[[Category:Viral diseases]]
[[Category:Betaherpesvirinae]]
[[Category:Virus-related cutaneous conditions]]
[[Category:Herpesviridae]]
[[Category:Herpesvirales]]