Fig. 7. Model for placement of prehair initiation in Drosophila. Diagram representing a z-section of apical regions of a cell, showing distal complexes (green) and proximal complexes (orange). The proximal complex recruits In, Fy and Frtz (red), which in turn recruit or activate an unknown kinase (pink) that modifies Mwh (magenta), which is consequently stabilised in apical/proximal regions. Mwh acts as an inhibitor of actin filament formation in electron-dense pimples on the surface of cells (dark grey), possibly by interfering with the activity of conventional formins. Distally in the cell, pimples become activated as a consequence of a lack of Mwh activity. The distal complex promotes pimple activation, either by repression of Mwh activity or via an alternative mechanism.