Misshapen regulates integrin levels to promote epithelial motility and planar polarity in Drosophila. Lindsay K. Lewellyn, Maureen Cetera, Sally Horne-Badovinac. Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL.

   Complex organ shapes arise from the coordinate actions of individual cells. The Drosophila egg chamber is an organ-like structure that lengthens along its anterior-posterior axis as it grows. This morphogenesis depends on an unusual form of planar polarity in the organs outer epithelial layer, the follicle cells. Interestingly, this epithelium also undergoes a directed migration that causes the egg chamber to rotate around its anterior-posterior axis. However, the functional relationship between planar polarity and migration in this tissue is unknown. We have previously reported that mutations in the Misshapen kinase disrupt follicle cell planar polarity. Here we show that Misshapens primary role in this system is to promote individual cell motility. Misshapen decreases integrin levels at the basal surface, which facilitates detachment of each cells trailing edge. These data provide mechanistic insight into Misshapens conserved role in cell migration. They also suggest that follicle cell planar polarity may be an emergent property of individual cell migratory behaviors within the epithelium.