Late transcription and simultaneous replication of simian adenovirus 7 DNA as revealed by spreading lytically infected cell cultures.

Miller's technique of spreading DNA was applied to monkey cells productively infected with simian adenovirus 7. This permitted the visualization of cellular DNA transcription, both nucleolar and non-nucleolar, and of late transcription and replication of virus. Virus double-stranded DNA, thin fibres with very few nucleosome-like particles, were observed carrying either transcription or replication complexes. In addition, both RNP transcripts and replication forks were found on some virus duplex DNA. Virus single-stranded DNA replicative intermediates were identified on the basis of their increased thickness and contrast which results from the presence of a DNA binding protein.