Dynamic cell shapes and contacts in the developing Drosophila retina are regulated by the Ig cell adhesion protein hibris.

Cell shapes and contacts are dynamically regulated during organogenesis to enable contacts with relevant neighboring cells at appropriate times. During Drosophila larval eye development, an apical contact is established between one pair of non-neuronal cones cells, precluding contact between the opposing pair. Concurrent with changes in cell shape, these contacts reverse in early pupal life. The reversal in cone cell contacts occurs in a posterior to anterior gradient across the eye, following the developmental gradient established in the larval eye imaginal disc. Hibris (Hbs), an Immunoglobulin cell adhesion molecule homologous to vertebrate Nephrin, is required for cone cell morphogenesis. In hbs null mutants, a majority of cone cells fail to both establish wild-type contacts and achieve mature cone cell shapes. hbs acts cell autonomously in the cone cells to drive these changes. The work presented here indicates hbs contributes to the remodeling of cell contacts and cell shapes throughout development. 2009 Wiley-Liss, Inc.