from Zsolt Ruzsics, Eva M. Borst, Jens B. Bosse, Wolfram Brune and Martin Messerle writing in Cytomegaloviruses: From Molecular Pathogenesis to Intervention:
Cloning of a CMV genome as a BAC was reported for the first time more than a decade ago, and since then this approach has virtually opened the avenue for unrestricted mutagenesis of CMVs. This review gives an overview of recent developments in BAC-based mutagenesis techniques and their application to specific questions of CMV biology. One focus is on mutagenesis of essential CMV genes and the design of complementation strategies, as well as on conditional CMVs that allow the analysis of this class of viral genes in vitro and in vivo.
Further reading: Cytomegaloviruses: From Molecular Pathogenesis to Intervention