Journal: Science advances
Article Title: Single-molecule imaging of transcription at damaged chromatin.
doi: 10.1126/sciadv.aau1249
Figure Lengend Snippet: Fig. 3. Break-induced transcription initiation. Time-lapse, multiplane, spinning disk confocal microscopy recordings of EX2 reporter transcription dynamics in live cells revealed by the dual labeling of nascent transcripts with MS2-RFP and PP7-GFP in the absence [(A) no TA] or upon [(B and C) +TA] DNA damage. The dual-line plots represent the number (n) of transcripts detected at the transcription site over time. The bar graph in (A) shows the frequency of cells that exhibit a pattern of continuous (Contin.) and suppressed/terminated (Term.) transcription. The bar graph in (B) shows the frequency of cells, where preexisting transcription was sup- pressed in response to TA treatment and either resumes (Resume) or remains silenced (Term.) during the entire imaging period. A representative pattern of transcription resuming is depicted on the images and dual-line plot in (B). (C) Representative images and dual-line plot of a recorded cell where only the PP7-GFP fluorescence is observed after the damage-induced termination and before dual-labeled transcripts are detected. The bar graph depicts the frequency of cells that exhibit a similar uncoupling of the MS2-RFP and PP7-GFP fluorescent signal (Uncoupl.) and those where transcription resumed as illustrated in (B) (Coupl.). (D) Western blot analysis of DNA ligase IV in control (ctrl) or DNA ligase IV small interfering RNA (siRNA)–depleted cells. a-Tubulin and total histone H3 serve as loading controls. The bar graph depicts the frequency of cells that either resume or irreversibly terminate transcription after induction of the DSB in DNA ligase IV–depleted cells. kd, knockdown; RNAi, RNA interference.
Article Snippet: The 24 PP7 stem-loop sequence was excised from pCR4-24xPP7SL [Addgene plasmid no. 31864 (28)] by Bam HI and Bgl II digest and inserted into the Bam HI site of pCMV5-24xMS2SL, generating pCMV5-24xMS2SL-24xPP7SL.
Techniques: Confocal Microscopy, Labeling, Imaging, Fluorescence, Western Blot, Control, Small Interfering RNA, Knockdown