Shope rabbit papillomavirus (SRPV), a member of Genus papillomavirus of Family Papovariridae, causes benign tumors (papillomas) of squamous epithelium both in its natural host, i.e.,, cottontail rabbits and in its artificial host, i.e., domestic rabbits. So far, SRPV has never been successfully cultivated in tissue culture cells, and the lack of reliable tissue culture system for transformation
1 assay has seriously hindered the progress in the oncogenic study of this well-known DNA tumor virus. Therefore, the only possible way of obtaining SRPV in the laboratory is to inoculate cotton-tail rabbits with SRPV and to harvest the virus-loaded papillom.a tissues.
This study was undertaken 1) to isolate SRPV DNA from SRPV-induced papillomas of either cottontail rabbits or domestic rabbits, 2) to determine the restriction endonuclease cleavage sites of such purified SRPV DNA, 3) to carry out cloning of SRPV DNA in E. toll with the use of pBR322 vector and 4) to test the oncogenicity of cloned SRPV DNA-pBR322 recombinants in the domestic rabbits through inoculation experiments. The results are summarized as follows.
1. Though repeated attempts failed to isolate purified Shope rabbit papillomavirus DNA from the domestic rabbit papilloras (DRP), a good yields of purified SRPV DNA were successfully isolated from the cottontial rabbit papillomas (GRP).
2. With the purified SRPV DNA from CRP, the presence of cleavage sites for a number of restriction endonucleases was confirmed and extended, and the approximate molecular length of isolated SRPV DNA was_determined to be 8 kbp.
3. Molecular cloning of isolated SRPV DNA was completed in E: tali YMC-10, using pBR322;as
the vector, at the Eco RI and Sal I cleavage site, respectively. The cloned products were either
Eco RI-site cloned SRPV DNA-pBR322 recombinant or Sal I site-cloned SRPV DAN-pBR322
recombinant.
4. Inoculations of cloned SRPV DNA-pBR322 recombinants into the domestic rabbits´ skin failed to .establish the oncogenic potential of the cloned products.
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