Live-cell imaging of transcriptional activation following TSA treatment. Live-cell imaging of transcriptional activation following TSA treatment. (A) Frames from Video 1 showing the activation of the CCND1-MS2 allele under the control of the CMV promoter during TSA treatment. The cell is expressing MS2-CP-GFP. The plot shows the levels of intensity on the active gene over time. Time 0 is the time of TSA addition to the cells. (B) Frames from Video 2 showing the activation of duplicated CCND1-MS2 alleles (CMV driven) during TSA treatment. (C) Frames from Video 3 showing an active single CCND1-MS2 gene (CMV driven), its transition to a duplicated state, and the subsequent activation of the duplicated CCND1-MS2 alleles during TSA treatment. Scale bar, 5 μm. Sharon Yunger et al. LSA 2018;1:e201800086 © 2018 Yunger et al.