Figure 4

Qualitative changes in SNAI1-DN cell migration. In a wound healing assay, cells are fixed one, three and five hours after wounding. Together with the individual versus collective migration, morphological characteristics reinforce the epithelial to mesenchymal transition (EMT) status of MDA-mock and inverse transition for SNAI1-DN cells. (a) Actin immunostaining show that the MDA-mock cells move as individuals or as small groups of cells. The remaining population is not organised as a coherent group but rather as a juxtaposition of individuals. This is attested to by the presence of small groups of cells or individuals (white arrows) distinct from the leading edge (white line). In contrast, SNAI1-DN cells, moved as a coherent group, with a unique leading edge and large lamellipodia underlined by actin staining (see also figure 5). (b) This picture (at four times lower magnification) generalises the individual versus collective behaviour of the MDA-mock and SNAI1-DN cells at the wound scale.