The long range objectives of this work are to characterize the mechanism of herpes simplex virus type 1 (HSV-1) gene expression and its control during productive infection of human cells. This proposal focuses mainly on the characterization of transcription which takes place in the absence of protein synthesis--immediate early gene (IE) transcription. This will be investigated through studies on 1) UV-mapping of viral polypeptides and mRNAs, 2) isolation and characterization of IE mRNAs, 3) the structure and translation of IE mRNAs 4) genome mapping of IE mRNAs by hybrid arrested translation, blot hybridization, and R-loop electronmicroscopy. Subsequent studies will focus on the characterization of the delayed early RNAs. These studies will provide data on the size of primary transcripts, genome location of promoters, transcriptional units, mRNA sequences, and on the direction of transcription of HSV-1 genes.