Synchronization of a synthetic gene oscillator in Escherichia coli

Tal Danino, University of California, San Diego

We previously constructed a synthetic E. coli gene network which produces oscillations due to a delayed negative feedback loop. After a few cell divisions, the oscillations of proteins between neighboring cells lose synchrony and produce a wide variability in oscillation phase across a population. We experimentally constructed an intercellular quorum sensing circuit that enables a population of cells to synchronize. The design allow for cells to communicate their phases via the luxIR system from Vibrio Fischeri. The luxI synthase produces a small molecule, AHL, which can diffuse to neighboring cells and induce the luxI promoter. We find that the period of oscillation can be tuned by varying the flow-rate in our microfluidics devices. We discuss our model for these results and the rich spatio-temporal dynamics of this system.

Abstract Author(s): Tal Danino, Octavio Mondragon, Lev Tsimring, Jeff Hasty