Transcriptional bursting of a mammalian gene after stimulation
Increasing evidence from single cell studies indicates that gene transcription in mammals is fundamentally stochastic, occurring in short and intense transcriptional bursts followed by longer ‘off’ time. However, how these ‘on’ and ‘off’ transitions are modulated in single cells to increase gene expression upon stimulation is poorly characterized.
In a January 2014 publication in PNAS, the groups of David Suter and Felix Naef at the Institute of Bioengineering (IBI-SV) monitored the transcriptional response of a single allele of the endogenous ctgf gene, encoding a secreted protein involved in wound healing and response to shear stress, to two different physiological stimuli in single cells. By combination of single cell time-lapse luminescence imaging with stochastic modeling, the researchers showed that the stimuli acutely modify the durations of ‘on’ and ‘off’ periods and increase transcription rates for short or long periods, depending on the stimulus. These results provide novel insights on how transcriptional bursting kinetics can be adjusted to increase gene expression upon physiological stimulations.
Movie legend: Single cell transcriptional response of the CTGF gene after stimulation, with a temporal resolution of 1 minute