Repressor lattice: feedback, commensurability, and dynamical frustration.

We construct a hexagonal lattice of repressing genes, such that each node represses three of the neighbors, and use it as a model for genetic regulation in spatially extended systems. Using symmetry arguments and stability analysis we argue that the repressor lattice can be in a nonfrustrated oscillating state with only three distinct phases. If the system size is not commensurate with three, oscillating solutions of several different phases are possible. As the strength of the interactions between the nodes increases, the system undergoes many transitions, breaking several symmetries. Eventually dynamical frustrated states appear, where the temporal evolution is chaotic, even though there are no built-in frustrations. Applications of the repressor lattice to real biological systems are discussed.