Fig. 4.

(A) Expression pattern of U created by the substrate gradients in Fig. 3. The morphogens form a hexagonal pattern within the area of a hair bundle. (B) Rotated view of a 3D reconstruction of the hair bundle, derived from the blueprint shown in A. The concentration peaks of U specify the locations of stereocilia whose lengths are proportional to the concentration of A. The length of the kinocilium is arbitrary and not predicted from the model. Parameter values are $\gamma =10,000$, $d_u=0.8$, and $d_v=16$.