Figure 3. Sequential and morphogen-based inductions are found for different parameter sets of the model.

(A) Tests for morphogen-based versus sequential induction in the model. The simplified intercellular network characteristic of each patterning mechanism is shown on the right, with the color code from Fig 1. (B) Robustness of the vulval induction network to parameter variation. Graph showing the fraction of solutions (y-axes) that produced a stable wild-type pattern after 10-fold variation in the specified parameter (x-axes) (n=300 solutions from each mode). High values (close to 1) indicate insensitivity to the 10-fold parameter change. (C) Network diagrams indicating the interaction strength characteristic of the patterning mode, as defined by parameter values for the corresponding step: for example, a low k value is expressed as a strong interaction. These networks summarize the results of the Kolmogorov-Smirnov test comparing parameter distributions of wild-type solutions against solutions from each mode (Table S4 and Fig S3A). Two parallel bars on an arrow indicate low cooperativity. (D) Schematic representation of model parameter space in two dimensions. The parameter sets that produce the wild-type pattern, each patterning mode, “C. elegans” (AC ablation and egf overexpression criteria only) and “C. elegans N2” are schematically represented as a fraction of space (other species sets are omitted for simplicity). See also Figure S3 and Tables S3, S4.