FIG. A1.

Effect on fruiting body formation in the computational model where head-to-head signaling resets the internal clock. The images are taken after 5 h of cell time (i.e., time in the simulations) in the early stages of fruiting body formation. (a) No signaling. (b) Strong collision signaling speeds up the clock (as in references 5, 6, and 18). Fruiting body formation is delayed, and as a result we can see small early aggregates. (c) Strong density-dependent slowing of the clock (possibly the effect of EPS and/or C-signal). The fruiting bodies are elongated, similar to the Frz deletion mutants, wherein the reversal rates are reduced. (d) Combination of both signaling effects. In combination, these effects effectively compensate each other, leading to fruiting bodies similar to those in panel a.