MBExC Lecture

Chairs: Tobias Moser and Timo Betz

Prof. Erez Raz, Institute of Cell Biology, ZMBE, University of Münster, Germany
will talk about “Germ-cell migration in zebrafish – motility, directed migration and stop at the target“.

Abstract

Zebrafish primordial germ cells (PGCs) migrate throughout the embryo towards the site where they give rise to sperm and egg. In this process, PGCs employ a bleb-driven amoeboid migration mode characterized by low adhesion and high actomyosin contractility, a strategy employed by many other cell types. During their migration the motile PGCs are guided towards their target by the chemokine Cxcl12.

In this talk the cellular mechanisms facilitating cell polarization, protrusion formation and directed migration of the PGCs will be presented. Specifically, we show that enhanced actin polymerization defines the cell front and that myosin contractility is essential for the formation of blebs at that aspect of the cell. Following the definition of the front, cytoplasmic flow away from it leads to the establishment of the back of the cell by transporting bleb-inhibiting linkers proteins in this direction. We provide evidence that the sole role of guidance cue Cxcl12 is to bias the initial positioning of the front of the cell in the direction of the attractant source. In the next steps, the front-back axis is stabilized, leading to persistent directed migration towards domains within the tissue, where the level of the attractant is elevated. Finally, the cellular events leading to maintenance of the cells at their target will be presented.

Poster of the talk