Movie 6.

Sevilletor implementation of the PORD model. 2D simulation of the PORD model implemented in the Sevilletor framework (Fig. 4E). Left: wild type simulation. Modulations promoted by R (k₁) and FG (k₃, k₄), and u and v signaling are shown side-by-side. All cells have k₁ = 0.0 and the simulation starts with a pre-patterned somite (high signaling at the top boundary). The virtual tail grows with a constant speed by addition of a line of cells at the bottom (posterior). A gradient of k₃ and k₄ changes the frequency along the x-axis to create phase waves. The model generates a periodic somite pattern by freezing cells due to a relay mechanism based on lateral inhibition. Right: Simulation with 5% multiplicative noise added to phase values (u, v) and 0.5% multiplicative noise to parameters (k₃, k₄). The PORD model is fragile to noise due to its tendency to generate lateral inhibition patterns.