Molecular Cloning and Restriction Endonuclease Mapping of Two Strains of Canine Adenovirus Type 2

The DNA of a field isolate and of a vaccine strain of canine adenovirus type 2 (CAV-2) were analysed by digestion with several restriction endonucleases. The PstI restriction fragments of the field isolate (CAV-2 Glasgow) and the vaccine strain were cloned into the plasmid pBR322. Physical maps of the two viral genomes were constructed by molecular hybridization of PstI, EcoRI, SmaI, BamHI and KpnI digests of the viral DNA with the cloned PstI fragments. The restriction profile of CAV-2 Glasgow was shown to be virtually identical to those of the two prototype CAV-2 strains, Toronto A26/61 and Manhattan. However, the restriction fragment pattern of the vaccine strain of CAV-2 showed characteristic alterations, in particular additional sequences at or near the genome termini.