Genomic relationship between capripoxviruses.

Capripoxvirus DNAs from field isolates and vaccine samples were analysed by digestion with the restriction enzyme Hind III. The patterns of fragments generated by digestion with Hind III are sufficiently similar to show that all capripoxviruses are closely related, although patterns of different isolates can be grouped in a way which correlates with the animal of origin. The close relatedness was also demonstrated by the high level of sequence homology detected using the Southern Cross hybridization system. Despite the sequence homology, the molecular weights of the genomes of different isolates varied from 73 to 91 MDa. The presence of two rapidly reannealing restriction fragments in the Hind III digests of capripoxvirus DNA indicated the presence of terminal cross-links.