Network Motif Dynamics
Feed-forward loops and other motifs — signal processing in gene regulatory networks
Motif Type
C1-FFL
I1-FFL
Auto-regulation
Bi-fan
Coherent type-1 FFL: delays transient signals, passes persistent signals
Input signal duration T:
10
Activation threshold K:
0.5
Degradation rate γ:
0.5
Replay
Motifs
are recurring subgraph patterns found more often than expected in random networks.
C1-FFL
: X→Y→Z and X→Z. Acts as a sign-sensitive delay: delays Z response to short signals, responds to persistent ones.
I1-FFL
: X→Y–|Z and X→Z. Y represses Z, creating pulse-like response.
Milo et al 2002 (Science): systematic identification of network motifs.