Gertrud M. Schüpbach

My research has focused on the developmental mechanisms that establish pattern and polarity using Drosophila melanogaster as model organism. We have shown that during oogenesis localized activation of the Drosophila EGF receptor plays a crucial role in the establishment of both the anterior-posterior as well as the dorsoventral axis of the egg and embryo. Building on these results we have investigated mechanisms of RNA localization and translational control, and we have been investigating the response to EGFr activity, and the morphogenesis of the follicle cell epithelium.

We have isolated and characterized a number of maternally expressed genes that are crucial for the establishment of the major axis of the egg and embryo in Drosophila. In particular, we have shown that cell communication between the germ cells and the surrounding follicle cells is required to set up the initial asymmetries in the egg that ultimately lead to correct patterning of the embryo. Signaling from the oocyte to the follicle cells involves the Drosophila EGF receptor and its ligand, Gurken. Localization of gurken mRNA in the oocyte is crucial for the localized activation of EGFR in the follicle cells and we have identified factors that are involved in this localization process. We have also shown that a meiotic checkpoint exists that can downregulate the translation of Gurken. In addition, we have identified factors required in the follicle cells to respond to EGFR signaling, and for follicle cell polarity and differentiation.