Fig. 4

Reaction–diffusion simulation can explain the patterning of avian reticulate scales. Whole-mount ISH revealed that reticulate scale development begins with a circular domain (A, white arrowhead P), which subsequently subdivides into smaller secondary units, radiating outwards sequentially out from a central unit (B–D, white arrowhead S). RD simulation suggests that interactions between diffusing activatory and inhibitory morphogens can explain this patterning process (E–H). See “Methods” section for further details of RD modelling. Scale bars are 250 µm in length