Transcription expressed by isolated cell nuclei in relation to the cell cycle

In vitro transcription of stimulated T lymphocyte nuclei was studied using a previously described method for evaluating the accumulation of double labelled transcription products. Whereas RNA elongation was inhibited during the G0 and S phases of the cell cycle, the synthesis of short-living products (probably products of abortive initiation) still proceed in vitro. Release of the elongation block with concommitant decrease of short-product synthesis was observed during the G1 phase.