Skip to main content
. Author manuscript; available in PMC: 2010 Dec 11.
Published in final edited form as: Mol Cell. 2009 Dec 11;36(5):894–899. doi: 10.1016/j.molcel.2009.11.018

Figure 4. Fold-change detection may provide signaling advantages in noisy environment.

Figure 4

(A) Fold-change detection ensures that each cell responds reliably to an external signal despite variation in the basal level of X. In fold-change detection, cells sense relative changes from the basal level, and not absolute levels or absolute changes.

(B) Fold-change detection rescales the meaningful change in signal according to the background noise. In fold-change detection, ΔX = 1 when background X = 1 gives the same information as ΔX = 10 when background X = 10.

(C) Fold-change detection in the I1-FFL can provide a transcriptional analog of Weber’s Law in sensory system, which states that the minimal detectable change in signal scales linearly with the background signal.