Cell-Cell Interactions Controlling Organ Shape
The precise positioning of organ progenitor cells constitutes an essential, yet poorly understood step in organogenesis. Using zebrafish primordial germ cells (PGCs) as an in vivo model for this process, we propose to study the cellular interactions that contribute to the organization of this cell population with respect to other structures in the embryo, mechanisms that shape the early developing gonad. We have previously defined roles for structures that are important for maintenance of the separation between the two bilateral clusters of motile cells, as well as for limiting PGC migration in the dorsal direction and keep analyzing this early stage in gonad formation. Nevertheless, the later establishment of more stable interactions of the PGCs with tissues located in this region was not studied. The proposed project will first focus on the identification of additional cell populations the PGCs interact with. In addition we will identify molecules expressed in the environment and in the PGCs, molecules that are involved in the interactions leading to stable positioning of the cells within the developing organ. This will be followed by functional analysis aimed at determining the importance of the identified structures and molecules in controlling the 3-dimensional arrangement of the tissue.