Transcriptional pulsing of a developmental gene.
It has not been possible to view the transcriptional activity of a single gene within a living eukaryotic cell. It is therefore unclear how long and how frequently a gene is actively transcribed, how this is modulated during differentiation, and how transcriptional events are dynamically coordinated in cell populations. By means of an in vivo RNA detection technique , we have directly visualized transcription of an endogenous developmental gene. We found discrete "pulses" of gene activity that turn on and off at irregular intervals. Surprisingly, the length and height of these pulses were consistent throughout development. However, there was strong developmental variation in the proportion of cells recruited to the expressing pool. Cells were more likely to re-express than to initiate new expression, indicating that we directly observe a transcriptional memory. In addition, we used a clustering algorithm to reveal synchronous transcription initiation in neighboring cells. This study represents the first direct visualization of transcriptional pulsing in eukaryotes. Discontinuity of transcription may allow greater flexibility in the gene-expression decisions of a cell.
Chubb
Jonathan R
JR
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, The Bronx, New York 10461, USA. j.chubb@dundee.ac.uk
Trcek
Tatjana
T
Shenoy
Shailesh M
SM
Singer
Robert H
RH
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D004023:Dictyostelium / Q000166:cytology / Q000378:metabolism*; D005057:Eukaryotic Cells / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D050437:Genes, Developmental; D007700:Kinetics; D012333:RNA, Messenger / Q000096:biosynthesis; D014158:Transcription, Genetic
D012333:RNA, Messenger