Transforming genes of canine adenovirus type 2

Genes of canine adenovirus type 2 (CAd2) involved in transformation were localized and their functions investigated. Cells transformed by CAd2 whole DNA or the BamHI A fragment (leftmost 47%) totally lacked contact inhibition and were serum-independent, anchorage-independent and tumorigenic in newborn rats. All the cells transformed by the XbaI D (0 to 15.2%) and the EcoRI C (0 to 11.3%) fragments were morphologically transformed, but were serum-dependent, anchorage-dependent and not tumorigenic in newborn rats after 150 and 190 days observation, respectively, when 5 x 10(6) cells per rat were injected. No transforming activities were detected by DNA fragments smaller than EcoRI C. By Northern blot hybridization, it was shown that a 1 kb mRNA was encoded in the 0 to 45% region of the genome, and 1.1 kb and 2 kb RNAs in the 4.5 to 11% region. It was therefore suggested that these gene products are required for morphological transformation, and other gene(s) or element(s), which have not been identified, may be involved in serum independence, anchorage independence and tumorigenicity of the transformed cells.