Front Propagation in an Array of Artificial Cells

Alexandra M. Tayar, Eyal Karzbrun, Vincent Noireaux, Roy H. Bar-Ziv

Living systems employ front propagation and spatiotemporal patterns, encoded in nonlinear biochemical reactions, for communication, self-organization, and computation Emulating such dynamics in minimal systems is important for understanding physical principles in living cells and in vitro. Here, we report a 1D array of DNA compartments in a silicon chip as an artificial multicellular system, offering means to implement reaction-diffusion dynamics by integrated genetic circuits and chip geometry. Using a bistable circuit we programmed a sharp front of protein synthesis propagating in the array as a cascade of signal amplification and short-range diffusion. The front velocity is maximal at a saddle-node bifurcation from a bistable regime with traveling fronts to a monostable one that is spatially homogenous. Near the bifurcation the system exhibits large variability between compartments, providing a possible mechanism for population diversity not due to stochastic fluctuations. This puts forth a man-made biological system with programmable information processing from genes to cells and up to the multicellular scale. 

Nature Physics 11, 1037–1041 (2015) doi:10.1038/nphys3469