Network Motifs — Feed-Forward Loop & Autoregulation

Biological transcription network motifs: FFL (coherent/incoherent), autoregulation, their dynamics & functions

Motif topology

Gene expression dynamics

Motif type

α (prod rate) 8

β (degradation) 1.0

K (threshold) 2.0

Input signal

Steady state X: —

Steady state Y: —

Response time: —

Function: —

Alon (2007 Nature Rev Genetics): network motifs are statistically over-represented subgraphs with specific functions. C1-FFL: sign-sensitive delay (noise filtering). I1-FFL: pulse generator + response acceleration. Negative autoregulation: faster response + noise reduction. Each motif solves a specific gene regulation challenge.