Figure 7. Dynamic process leading to DV boundary establishment and maintenance.

(A) Snapshots of the concentration of species versus cell-number along an axis perpendicular to the DV border (dorsal is on the left and ventral on the right). The sequence shows how the expression pattern is generated from the initial condition (1) to the stationary state (6). Frame-to-frame time lapses differ. Dotted lines delimit a four-cell-wide region around the DV boundary and highlight the refinement process (see text). (B) Comparison between the Notch activity domains at different stages (early stages in pink, late stages in purple) that stress the refinement process.