Identification and characterization of herpesviral immediate-early genes

Immediate-early (IE) genes are the first class of viral genes expressed after primary infection or reactivation. As transcription of IE genes does not require prior viral protein synthesis, this class of genes is experimentally defined by their transcription following primary infection or reactivation in the presence of inhibitors of protein synthesis. This chapter describes an approach to identify IE genes in a novel herpesvirus genome. Transcription of IE genes is selectively induced with sodium butyrate in the presence of the protein synthesis inhibitor cycloheximide. The transcripts of the induced genes are identified by using a cDNA subtraction-based method of gene expression screening.