Non-repetitive DNA transcripts in nuclei and polysomes of polyoma-transformed and non-transformed mouse cells

Abstract

WE have determined the extent to which non-repetitive DNA is represented in nuclear and polysomal RNA of polyoma-transformed and non-transformed mouse cells in culture. Our RNA–DNA saturation-hybridisation experiments have shown that in transformed cells, polysomes contain only 10–20% of the informational complexity present in nuclear RNA. Similar results were obtained with RNA from confluent cultures of non-transformed cells. In subconfluent cultures of non-transformed cells, however, polysomes contained about 40% of the sequence diversity present in nuclear RNA. Further experiments, with appropriate RNA mixtures, suggest that there are also qualitative differences in polysomal RNA between transformed and non-transformed cells, as well as between confluent and subconfluent cultures of non-transformed cells.