Genome sequence of bovine herpesvirus 4, a bovine rhadinovirus, and identification of an origin of DNA replication

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus of cattle. The complete long unique coding region (LUR) of BoHV-4 strain 66-p-347 was determined by a shotgun approach. Together with the previously published noncoding terminal repeats, the entire genome sequence of BoHV-4 is now available. The LUR consists of 108,873 bp with an overall G1C content of 41.4%. At least 79 open reading frames (ORFs) are present in this coding region, 17 of them unique to BoHV-4. In contrast to herpesvirus saimiri and human herpesvirus 8, BoHV-4 has a reduced set of ORFs homologous to cellular genes. Gene arrangement as well as phylogenetic analysis confirmed that BoHV-4 is a member of the genus Rhadinovirus. In addition, an origin of replication (ori) in the genome of BoHV-4 was identified by DpnI assays. A minimum of 1.69 kbp located between ORFs 69 and 71 was sufficient to act as a cis signal for replication. Bovine herpesvirus 4 (BoHV-4) was isolated from cattle with various clinical symptoms, e.g., skin lesions, genital and respiratory diseases, and malignant catarrhal fever, and also from apparently healthy animals (reviewed in reference 28), although its pathogenic role remains unclear. BoHV-4 repli-cates in animal cell lines like Georgia bovine kidney cells, baby hamster kidney cells, Crandell feline kidney cells, and equine dermal cells as well as in human cell lines like human embry-onic lung cells and HeLa cells (16, 39). Due to its behavior in cell culture as well as its morphogen-esis, BoHV-4 was originally classified as a betaherpesvirus (36). The formation of high-density inclusion bodies and giant cells after infection of tissue culture cells, which is well-known for cytomegaloviruses, supported this initial classification (36