BOVINE HERPESVIRUS-4 - GENOMIC ORGANIZATION AND RELATIONSHIP WITH 2 OTHER GAMMAHERPESVIRUSES, EPSTEIN-BARR-VIRUS AND HERPESVIRUS SAIMIRI

Bovine herpesvirus 4 (BHV-4) belongs to the gammaherpesvirinae subfami ly. Although the whole sequence of BHV-4 genome is not known it was po ssible, based on random sequencing, to assume that its genomic organiz ation consists of genes clustered in blocks whose orientation and loca tion in the genome are conserved within a herpesvirus subfamily. Betwe en these blocks lie genes which are specific to either a particular vi rus or a virus subfamily. BHV-4 genome consists of 5 gene blocks conse rved among the gammaherpesviruses and particularly within the Epstein- Barr virus (EBV) and the herpesvirus saimiri (HVS) genomes. Analysis o f the regions located outside the gene blocks showed the presence of 1 2 open reading frames (ORFs). Protein database comparisons showed that no ORF translation products were similar to proteins encoded by alpha - or beta-herpesviruses. Nevertheless, 5 ORFs were homologous in amino acid sequences to proteins encoded by HVS and one was similar to a pr otein encoded by both HVS and EBV. On the basis of the molecular data BHV-4 is more closely related to HVS than to EBV. Genes homologous to cellular genes have been described in both HVS and EBV genomes. No gen es homologous to presently sequenced cellular genes were found among t hose found in the BHV-4 genome to date.