Nucleotide sequence and transcriptional analysis of a portion of the bovine herpesvirus genome encoding genes homologous to HSV-1 UL25, UL26 and UL26.5

We determined the nucleotide sequence of a 3811 base pair (bp) region of the bovine herpesvirus type-1 (BHV-1) HindIII-A fragment covering map units 0.429–0.456, which contained the HSV-1 homologues of the UL25, UL26 and UL26.5 genes. Sequence overlap was verified with previously published BHV-1 sequences, resulting in contiguous sequence spanning from UL24 to UL27 (encoding glycoprotein B). We found that the UL25 open reading frame (ORF) overlapped that of UL24 by 16 nucleotides, an unexpected feature baased on previous herpesvirus sequences. We previously showed that the BHV-1 UL26 and UL26.5 genes encoded proteins that functioned in proteinase and scaffolding activity during capsid assembly, similar to the homologues in herpes simplex virus type-1. Northern blotting was used to map the four major transcripts from this region. As expected from the ORF analysis, the BHV-1 UL25 transcript initiated within the UL24 ORF. The BHV-1 UL24, UL25, UL26 and UL26.5 transcripts all terminated at a common 3′-polyadenylation site and varied significantly in their relative abundance