In the fission yeast Schizosaccharomyces pombe microtubules are essential for specification of cellular domains, such as cell ends and the cell centre. During interphase, microtubules are required for the continuous delivery of polarity factors, to the tips of the cell. At the cell centre, microtubules are necessary for medial positioning of the nucleus, which in turn specifies the site of division and septum formation. However, it is still unclear how microtubules sense space and provide the cell with positional infonnation. Recently a kinase, Pom1p, enriched at both cell ends and the cell centre, has been shown to play a role in positioning and marking sites of growth and division, probably by regulating microtubules dynamics. The aim of the proposed work is to better define the role played by Pom1p in providing this spatial information. I will perform a suppression screen to identify components lying in the same pathway as PomI p kinase. This screen will allow the identification of targets and regulators of Pom1p, as well as proteins required for Pom1p localization. The requirement for Pom1p kinase localization and regulation will be further investigated by a structure-function analysis of Pom1p protein. I will also investigate the conservation of the components of this system in other model organisms, such as Drosophila melanogaster. The proposed project combines a wide range of cell biological and genetic approaches to issues cell polarization and morphogenesis in fission yeast and will therefore allow me to acquire familiarity with the system which provides a powerful tool to address cell biological issues in eukaryotes. This knowledge will be essential for carrying out the proposed work and also in my future independent carrier. As I am interested in understanding the implication of cell shape and morphogenesis in the organization of multicellular structures (tissue and organs) and in development (gastrulation), already in the host laboratory I will combine the use of fission yeast and Drosophila melanogaster towards the understanding of cellular morphogenesis in higher eukaryotes. As the host laboratory focuses mainly on the use of fission yeast as a model system, my background as a Drosophila geneticist will provide the expertise necessary to carry out such studies and will also provide a challenging opportunity for me to develop an independent scientific research project.