Morphogenesis of the follicular epithelium during drosophila oogenesis

Resum

The follicular epithelium of the Drosophila ovary is composed of a monolayer of highly polarized follicle cells. After several rounds of division, follicle cells undergo a number of cell migration events and rearrangements that involve changes in cell shape and polarity. One of such migrations is performed by a group of specialized cells termed border cells. Considering the suitability of Drosophila for genetic and cell biological studies, the follicular epithelium of the Drosophila ovary thus represents an excellent model system where to analyse cell migration, epithelial morphogenesis and cell polarity. The work reported in this Thesis demonstrates that: i) integrins are necessary to maintain the simple organization of the follicular epithelium. Furthermore, integrin-mediated signaling is shown to be required for the correct orientation of the mitotic spindle in epithelial follicle cells, a process that probably involves Myosin VI function. ii) Misshapen kinase is required for border cell migration independently of the JAK-STAT and slbo pathwasys. This kinase regulates the dynamics of the actin-cytoskeleton to direct the migration of the border cell cluster. In this context, Misshapen controlos not only the DJNK pathway, but also additional proteins.