Consider the two feed-forward loops below containing three transcription regulators A, B, and C, where A receives the input signal and C generates the output. In the so-called coherent loop (left), A activates C both directly and indirectly, whereas in an incoherent loop (right), A activates C via one route and inactivates it via the other. Answer the following question(s) based on these network motifs.

-Considering the two particular feed-forward designs shown, would you expect the coherent (C) or the incoherent (I) loop to have a stable output and respond best to input signals that are above a certain threshold? Write down C or I as your answer.

Question

Consider the two feed-forward loops below containing three transcription regulators A, B, and C, where A receives the input signal and C generates the output. In the so-called coherent loop (left), A activates C both directly and indirectly, whereas in an incoherent loop (right), A activates C via one route and inactivates it via the other. Answer the following question(s) based on these network motifs.
 
-Considering the two particular feed-forward designs shown, would you expect the coherent (C) or the incoherent (I) loop to have a stable output and respond best to input signals that are above a certain threshold? Write down C or I as your answer.

Quizplus · Accepted Answer

This also depends on the particular parameters of the system. However, coherent feed-forward motifs are generally more stable and more robust to perturbations.

Consider the Two Feed-Forward Loops Below Containing Three Transcription Regulators