The role of Wnt5 during Axon guidance

The main focus of this thesis is the study of the role of Wnt5 during central nervous system development in Drosophila. Wnt5, previously known as DWnt3, was identified as a gene required for proper central nervous system development. The finding that a Wnt protein, traditionally associated with other developmental functions, is also required for axon guidance during late embryogenesis provided exciting new insights in the broad mechanisms that are used to establish the stereotypical neuronal connectivity of the central nervous system. Subsequent experiments described in this thesis reveal that, during embryonic development of the central nervous system, Wnt5 seems to be acting through an alternative pathway which involves src mediated signaling through the fractured tyrosine kinase RYK/Drl. Furthermore, we show that Wnt5 signaling through RYK/Drl is also required for proper muscle development suggesting a common signaling pathway required for muscle attachment site selection as well as axon guidance.The work in this thesis was financially supported by the Netherlands Organization for Scientific Research (NWO) Financial support for the printing of this thesis was generously provided by: J.E. Jurriaanse Stichting, Koninklijke Nederlandse Academie voor Wetenschappen: Van Leersumfonds, Stichting Leids Universitair Fonds en Leica Microsystems Nederland b.v..UBL - phd migration 201