The toggle switch is a common subnetwork of gene regulatory networks in charge of pattern formation. A new study by Schaerli lab, published in Molecular Systems Biology, combines a synthetic biology framework and mathematical modeling to characterize the spatiotemporal properties of the toggle switch in Escherichia coli.
The formation of spatiotemporal patterns of gene expression is frequently guided by gradients of diffusible signaling molecules. The toggle switch subnetwork, composed of two cross‐repressing transcription factors, is a common component of gene regulatory networks in charge of patterning, converting the continuous information provided by the gradient into discrete abutting stripes of gene expression. The group of Prof. Yolanda Schaerli (DMF) built a synthetic toggle switch in Escherichia coli to understand and characterize the spatiotemporal patterning properties of the toggle switch. In collaboration with Dr. Rubén Perez-Carrasco, Imperial College London, quantitative measurements were combined with a mathematical model. The results show that the toggle switch can produce robust patterns with sharp boundaries and demonstrate how the position, timing, and precision of the boundary can be controlled. The study underscores the relevance of studying the dynamical context of a gene regulatory network in order to understand patterning processes. Moreover, the established engineering guidelines on how to control patterning with a synthetic network will be valuable for future applications, for example in engineered living materials.