Birhythmicity and Hard Excitation from Coupled Synthetic Feedback Loops
Figure 1
Schematic diagrams of the coupled two negative feedback genetic circuits. Panel (a) is the transcriptional regulation networks for two different coupled negative feedback loops. panel (b) is the simplified and separated schematic diagram of panel (a). In panel (b), the black circle and the white circle are of opposite regulating functions, namely, “activation + repression ” shown in panel (c) or “repression + activation ” shown in panel (d). Arrows denote activation and “” symbols denote repression. The central negative feedback loop consists of three components (, , and ); meanwhile, the additional feedback loop consists of components , , , and .
