Modeling the genetic dual-feedback oscillator

From Q-bio

Recently, we constructed a genetic oscillator comprised of coupled positive and negative feedback loops. The robustness of the observed oscillations, however, challenged our understanding of the network, which was based on previous theoretical work. We find that a more complete model of the system not only quantitatively predicts the dynamics of the oscillator, but also changes our qualitative understanding of the mechanism behind oscillations. Introduction of several intermediate steps create a small delay in the feedback loops, leading to robust relaxation oscillations. Furthermore, our modeling predicts, and experiments confirm, that the system oscillates even in the absence of positive feedback.