Shope papillomavirus transcription in benign and malignant rabbit tumors.

Shope papillomavirus induced benign and malignant tumors from both wild and domestic rabbits were analyzed by the Northern blotting technique for the presence of viral-specific RNAs. Virus-producing benign tumors of wild cottontail rabbits are shown to contain two major RNA species approximately 5000 and 3000 bases in length that originate in the early region and include the majority of the L1 and L2 late open reading frames. Non-productive tumors including wild-rabbit carcinomas, and benign warts and primary and metastatic carcinomas of domestic rabbits uniformly are shown to contain two major viral-specific RNA species, 2400 and 1400 bases in length. These transcripts map entirely within the early region of the viral genome. In addition, Southern blot analysis of metastatic tumors indicates that the viral DNA remains exclusively extrachromosomal and apparently unrearranged supporting previous findings with epithelial malignancies.