Figure 3.
Graphical illustration of how a shift in the boundary separating two regions of attraction can result in phenotype switches under small perturbations. In the left panel, a perturbation of the silenced state leads to a transient configuration that belongs to the basin of attraction of the active steady state, resulting in a phenotype switch to the active steady state (i.e, the somatic state). In the right panel, the boundary has shifted, reflecting that fact that the relative sizes of the two basins of attraction have exchanged dominance. Now the same perturbation keeps the state in the domain of attraction of the silenced state, and the perturbed state eventually returns to that attractor. The shift in boundary could be due, for instance, to an increase in the methylation rate parameter