THE BIOLOGY OF BOVINE HERPESVIRUS-4

Bovine herpesvirus 4 (BHV-4) is an ubiquitous herpesvirus of cattle. It has been isolated from a variety of diseases without being recognised as the etiological agent of a defined disease, with the exception of postpartum metritis. The viral genome was characterised. It contains a unique sequence of double-stranded DNA of 110 kb, flanked at both ends by tandem repeated 1450 to 3050 bp long sequences. BHV-4 is a gammaherpesvirus which shares strong genomic homologies with herpesvirus saimiri (HVS) and, to a lesser extent, with Epstein-Barr virus (EBV). Gene arrangement in BHV-4 is collinear with HVS and EBV genomes: five blocks of genes are conserved among these viruses. BHV-4 proteins, especially glycoproteins, are expressed in a cascade fashion, like the other herpesviruses. Herpesviruses isolated respectively from cat and owl monkey (Aotus trivirgatus) are in fact strains of BHV-4. The range of species susceptible to BHV-4 is therefore extended to other animal species than ruminants.