CHARACTERIZATION OF THE HEMORRHAGIC ENTERITIS VIRUS GENOME AND THE SEQUENCE OF THE PUTATIVE PENTON BASE AND CORE PROTEIN GENES

Haemorrhagic enteritis virus (HEV) is a member of a genetically ill-de fined group within the genus Aviadeno-virus which causes significant c linical disease in gallinaceous fowl. Using DNA obtained from a low vi rulence isolate of HEV passed in turkeys, we developed a genomic restr iction map and estimated an apparent genomic length of 25.5 kb. No evi dence for extensive DNA hybridization was found between the HEV genome and either the hexon or penton base genes of human adenovirus 2 (HAdV -2) and fowl adenovirus 10 (FAdV-10). The HEV penton base gene was ide ntified by PCR using primers based on conserved adenoviral DNA sequenc es. The penton base gene was expressed in Escherichia coli as a fusion protein and detected by anti-HEV serum in both colony and denaturing gel immuno-blots. DNA sequencing revealed a putative penton base ORF w ith a predicted amino acid sequence showing approximately 39.0%, 53.0% and 44.2% similarity with the penton base of HAdV-2, human adenovirus 40 (HAdV-40) and FAdV-10, respectively. The penton base gene was loca ted at 43.3-48.6 m.u. on the HEV genome and had a remarkably low G + C content (33.8 %). DNA sequencing also revealed ORFs for putative core proteins resembling pVII, p-mu and a partial ORF similar to pVI (hexo n-associated protein) of HAdV-2 and HAdV-40. The results support the c laim that HEV represents a distinct group of viruses within the genus Aviadenovirus.