Abstract
Hybridization measurements among the DNA's of six weakly tumorigenic strains of human adenovirus type 7 reveal that all six strains are very closely related (83- to 110-percent nucleotide sequence homology). The DNA homology between these six type 7 strains and nontumorigenic types 2 and 4 is 32 percent and 52 percent, respectively. The 10- to 20-percent homology between the type 7 DNA's and those of "potent" tumorigenic types 12 and 18 indicates a very low degree of genetic relatedness. These data indicate that, if the carcinogenic potential of adenovirus types 7, 12, and 18 lies in the possession of nucleotide sequences common to these three viruses, these regions represent a small portion of the total genome, approximately one to three viral cistrons.