Complementation of an adenovirus 5 immediate early mutant by human cytomegalovirus

The initiation of the lytic cycle of adenovirus 5 requires synthesis of a transcriptional activator encoded by the viral early genetic unit, E1a. Mutant viruses lacking E1a are defective. Human cytomegalovirus activated transcription of early adenovirus genes and complemented an E1a- adenovirus mutant in cells permissive for both viruses.