Calcium signaling and formation of cellular protrusions in zebrafish germ-cell migration

• Applicant: Professor Dr. Erez Raz
• Subject Area: Developmental Biology
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 36289589

In sexually reproducing organisms, primordial germ cells (PGCs) give rise to gametes that are responsible for the development of a new organism in the next generation. An important feature of primordial germ cells is that they migrate from the position where they are specified towards the position of the gonad where they differentiate into gametes. This behavior serves as a general in vivo model for cell migration in multi-cellular organisms with the aim of understanding the mechanisms controlling cell motility and directional migration. Whereas the signal that guides the cells and the receptor that binds it are known (SDF-1a and CXCR4b respectively) the precise downstream signaling events leading to cell polarization and directed migration are not known. We have found that calcium regulated myosin contraction powers the formation of cellular protrusions and that activation of CXCR4 directs this process to the leading edge of the cell. More specifically, myosin contraction results in the separation of the membrane from the cell cortex that facilitates cytoplasmic flow and expansion of the forming bleb. The goal of this research proposal is to further investigate the molecular and cellular mechanisms responsible bleb formation and to explore the relevant events occurring at the onset of cell motility.

• DFG Programme: Research Grants