Cell diversity may arise at the moment of cell division when the cytoplasmatic determinants or membrane properties are asymmetrically distributed to the daughter cells. The asymmetric cell divisions rely therefore on the co-ordination of cell fate determinant localisation with the mitotic cleavage plan.This proposal will test the novel hypothesis that components of the vertebrate Planar Cell Polarity (PCP) pathway play critical roles in the control of progenitor divisions and neuronal fate determination in the vertebrate brain. We have evidence that the transmembrane protein Vangl2 is asymmetrically localised within zebrafish neuronal progenitors and may be required to determine orientation of progenitor cell mitoses.We will use zebrafish embryos to explore the regulation of Vangl2 localisation and the possibility that Vangl2 and other members of the PCP pathway are important regulators of neurogenesis. We will also determine whether the defective neurogenesis could be linked to the mitotic cleavage plan.And finally, whether PCP pathway controls the localisation of the cell fate determinant, Numb. Understanding the development and function of the brain is a key goal for research within the European Research Area.This work will greatly increase our knowledge of the molecular mechanisms controlling the neurogenesis, a fundamental step in brain development. We will use the zebrafish embryo as this allows single cell visualization and a quick and successful analysis of gene function.Together with the previous experience in classical embryology, this training will provide the candidate with new scientific and technical skills important to becoming an independent scientist.