The role of RNA molecules in transduction of the proto-oncogene c-fps.

Transduction of cellular genes by retroviruses requires two recombinations: one to form the left-hand junction between cellular gene and viral genome, the other to form the right-hand junction. Previous findings raised the possibility that the right-hand recombination might use RNA molecules as intermediates. We now provide direct experimental support for this view by showing that the right-hand end of v-fps in the avian sarcoma virus PRCII was formed by recombination within the poly(A) tract at the 3' end of the mRNA for the proto-oncogene c-fps. Recombination of this sort may be mediated by "copy-choice" during reverse transcription, acting on either homologous or non-homologous nucleotide sequences.