Figure 5.

Collective migration of mesoderm progenitor cells in zebrafish gastrulation. (A) Convergence and extension movements of lateral mesoderm cells during zebrafish gastrulation. Lateral view of zebrafish embryo at onset and end of gastrulation. A group of mesoderm cells is highlighted. Cells migrate towards the dorsal side and undergo mediolateral cell intercalations. Both cell migration and intercalations contribute to convergence and extension of the forming body axis. (B) Collective migration of lateral mesoderm cells. Cell elongation is driven by integrin-ECM adhesion and Wnt/PCP signals, which together modulate Rho-family GTPase activity. BMP signalling polarizes protrusion formation in individual cells. E-cadherin-mediated cell cohesion mechanically couples and thereby aligns the movements of neighbouring cells. In addition, E-cadherin restricts movement of cells over each other.