C1 Feed-Forward Loop Motif

Gene Network Architecture — Coherent Type 1 FFL Dynamics

Motif Type

Parameters

Steady States

X*1.00
Y*
Z*
Delay (ON)
Pulse (I1)

Theory

dY/dt = β_Y·f_XY(X) − α_Y·Y
dZ/dt = β_Z·f_XZ(X,Y) − α_Z·Z

C1 coherent: X→Y→Z & X→Z (all +)
Role: delay ON, quick OFF

I1 incoherent: X→Y−⊣Z & X→Z
Role: pulse generator, fold-change detection

Hill activation: f = Xⁿ/(Kⁿ+Xⁿ)