Distribution of sequences homologous to the DNA of herpes simplex virus, types 1 and 2, in the genome of pseudorabies virus

The distribution of related sequences between the genomes of pseudorabies virus (PRV) and herpes simplex virus, types 1 (HSV-1) and 2 (HSV-2), was determined. Approximately 7% of the sequences in PRV are shared by HSV-1 and HSV-2 DNAs. By means of the Southern blot technique, it was found that the homologous sequences are not sequestered in one region but are distributed throughout the PRV genome. HSV-1 and HSV-2 have the greatest homology with the long unique region of PRV DNA and the least with the inverted repeat regions of the molecule. HSV-1 DNA also has few sequences homologous to the short unique region of the PRV genome; HSV-2 DNA hybridizes well to this region. There was no homology of HSV-1 or HSV-2 DNAs with the extreme ends of the inverted repeat regions of PRV DNA.