Figure 3.

Simulated fusion of two embedded cell types places the resulting cell into one of numerous spurious states. (A) The evolution of the hybrid between Plane and Key (see also Movie S3). (B) Fusing two cell types results in a set of diverse hybrids. The fusion table shows the final settled gene activity patterns of hybrids obtained by fusing Plane and Key with varied contribution of each of these cell types at 5% increments. The white quadrant (lower left) represents the states in which all genes acquire their basal activity, an equivalent of cell death. (C) Spurious states differ in their energy, as shown in this energy map of the hybrids displayed in B. A 3-D representation of this map is shown in Fig. S1. Spurious attractors (center of image) are heterogeneous, as manifested by the diverse colors on the map, and the depth of these colors. (D) Settling into spurious states takes longer than settling into embedded states. The image shows the average time to reach the final states displayed in B. A 3-D representation can be seen in Fig. S2. (E) Cell fusion can place cells into spurious attractors. Fusion of Plane to Key creates a product that is in the basin of a spurious attractor. The abundance of spurious attractors (Fig. 3, B–D) suggests that they can exist in patches that cover the space between embedded (normal) attractors.