Summary:
The expression patterns of the segment-polarity genes engrailed and wingless, initially activated by the pair-rule genetic module, are consolidated along the anterior-posterior axis of the embryo trunk. The juxtaposition of engrailed (en) and wingless (wg) expressing cells determines the formation of the parasegmental boundaries: cells expressing en (resp. wg) mark the anterior (resp. posterior) region of each parasegment.
Relying on the original model presented in [1] (see also the model available in the GINsim model repository, http://ginsim.org/model/SP), the model has been extended to a larger set of cells (here a 12x12 grid). All the results described in the original paper, can be reproduced with the present model.