Comparative Genomics Of Primate Cytomegaloviruses

The subfamily Betaherpesvirinae contains four genera and three species not yet assigned to genera. CMVs belong to this subfamily, and are usually reckoned to consist of primate viruses (such as HCMV) in the genus Cytomegalovirus, rodent viruses (such as MCMV) in the genus Muromegalovirus, and two of the unassigned viruses (GPCMV and tupaiid herpesvirus 1). In this chapter, we focus primarily on members of the genus Cytomegalovirus, which infect apes (including humans) and Old and New World monkeys. The genomes of nine of these viruses, representing six species, have been sequenced fully. They are distinguished by being among the largest and most complex in the family Herpesviridae, by exhibiting an extraordinary degree of interspecies and interstrain variation, and by all having suffered functional losses via mutation. These characteristics continue to contribute to the fascination and challenge of CMV genomics.