Fig. 4

Deduced interaction network between pigment cells and simulation. (A) Control network among the pigment cells deduced by the results described in this report. There are 3 control loops that start with and return to the melanophores. Control loop I (experiment shown in Fig. 3) contains 2 short-range negative effects and functions as a short-range positive-feedback mechanism. Control loop II (experiment shown in Figs. 1 and 2) contains a negative (short) and a positive (long) effect and functions as a long-range negative-feedback mechanism. Control loop III (experiment shown in Fig. 1) is a long-range negative-feedback mechanism. As a whole network, this system satisfies the need for local activation and long-range inhibition, which have been cited by mathematical studies as necessary conditions for Turing pattern formation. (B–D) Development of pigment patterns in real zebrafish and computer simulation. In the left 2 panels, fish pigment pattern of 16-dpf and adult (3 months) are shown for wild type (B), leo^t1 (C), and obe^tc271d (D). Sixteen-dpf patterns are almost identical because the juvenile melanophore lines along the horizontal myoseptum. Therefore, we used identical initial pattern in the simulation for B, C, and D. In the right 4 panels, the results of the simulation are represented. In E, the pattern of 3 days after the ablation and regenerated pattern (11) are shown in the left 2 panels. Initial pattern for this regeneration is a random pattern in the ablated region. Details of the simulation are in Experimental Methods and Simulation.