PORCINE ADENOVIRUSES TYPE-1, TYPE-2 AND TYPE-3 HAVE SHORT AND SIMPLE EARLY E-3 REGIONS

The nucleotide sequence of the E-3 region genes, the hexon associated protein pVIII genes, and part of the fiber genes coding for the N-term inal tail regions, of porcine adenovirus (PAV) types 1 and 2 were dete rmined. The sizes of the E-3 regions were found to be 1162 and 1222 bp , respectively. The five open reading frames (ORF) encoded within the sequenced regions of PAV types 1 and 2 shared a high degree of homolog y with the published sequences of the corresponding ORFs of PAV-3. The E-3 regions of PAV types 1, 2 and 3 were further characterized by Nor thern blot analysis and 5' and 3' end mapping of the transcripts by S1 nuclease analysis. The results of these experiments indicated that th e E-3 regions in these three viruses are shorter and simpler in organi zation than the E-3 regions of human adenoviruses. A potential promote r for the E-3 regions of these PAVs was identified.