Fig. 3

Scattering, wound-healing, and aggregation assays. a Scattering assays visualize how multicellular epithelial (MDCK) clusters disperse into migratory individuals in response to exogeneous biochemical stimulation (e.g. HGF). b Traction force microscopy reveals cell-generated forces on deformable substrates, which are localized at the cluster and cell periphery. Reproduced from [86] with permission. c Wound healing assays visualize the collective migration of sheet-like monolayers into unoccupied regions. Mammary epithelial (MCF-10A) cells at the migration front (wound edge) gain vimentin expression (vimentin immunolabeling, red), analogous to an EMT. Reproduced from Gilles et al. [88] with permission. d Mammary epithelial cells cultured with reduced levels of epidermal growth factor initially aggregate into multicellular clusters, analogous to a reverse mesenchymal-to-epithelial transition. GFP cytoplasm (white) with individual cell tracks (5h, red). Subsequently, leader cells transiently guide migration to link clusters together into spanning networks. Reproduced from [89] with permission