Transcription of the repetitive DNA sequences in polyoma-transformed and nontransformed mouse cells in culture.

RNA-DNA saturation hybridization experiments were used to estimate the extent of transcription of repetitive DNA sequences in polyoma-transformed and nontransformed mouse cells in culture. Measurements were made with RNA from nontransformed cells in both the subconfluent and confluent stages of growth, transformed cells in normal growth medium, and transformed cells grown in medium containing 5-bromodeoxyuridine, 3 mu-g/ml, a treatment which reduces their tumorigenic potential. No differences were observed in the amount of repetitive DNA transcribed or in the families of sequences expressed, except in transformed cells grown in the presence of 5-bromodeoxyuridine, in which case the extent of transcription was reduced.