Cytomegalovirus (CMV) is a member of the Herpes virus family. Members of this family have a characteristic virion structure. The double stranded DNA genome is contained within an icosahedral capsid which is embedded in a proteinaceous layer (tegument) and surrounded by a lipid envelope that is decorated with virus-specific glycoprotein spikes. The viral genes are co-ordinately expressed in groups at various times after infection. Early viral proteins are expressed in the nucleus of infected cells within 3 to 24 hours of infection prior to the commencement of viral DNA replication. This is followed by expression of the early intermediate genes, which encode enzymes required for viral DNA replication. After 48 to 72 hours, a number of late viral antigens may be demonstrated in the nuclei and cytoplasm of infected cells.
Cytomegalovirus strain AD169 is a laboratory-adapted strain and appears to lack a 15kb region of the 200kb genome that is present in clinical isolates. This region contains 19 open reading frames whose functions have yet to be elucidated. AD169 is also unique in that it is unable to enter latency and nearly always assumes lytic growth upon infection.
has not yet been referenced specifically in any publications.