A Design Principle of Group-level Decision Making in Cell Populations
Figure 2
Graded and all-or-none transitions in a simple autoinduction circuit.
(A–B) In the population of simple autoinduction circuits (Fig. 1C; Eq. 1), the time average of the synthetase concentration xi within individual cells at the steady state (upper panel) and the fraction of ON cells (xi>0.5; lower panel) are plotted as a function of normalized cell density ρV; ε = 2.5 (A) and 0.25 (B); λ = 100 (A–B). Data points in the lower panel were calculated from multiple randomized sets of threshold ki with identical standard deviations. An analytically derived steady state for the population mean (dashed line; Eq. S2-1 in Text S1) indicates group-level bistability for
= 2∼5 (B). (C–D) Change in the distribution of xi for various cell densities: a bimodal distribution at high ε (
; C) and a unimodal distribution at low ε (D). ε = 2.5 (C) and 0.25 (D). λ = 100 (C–D).