Figure 4: Mechanical force and Notch signalling regulates the formation of leader cells.

(a) Effects of traction force-modulating reagents on Dll4 mRNA expression near the leading edge. Cells were transfected with dsLNA to detect the distribution of Dll4. (b,c) Effects of co-treatment of DAPT (b) or Jagged-1 (c) and cellular force-modulating reagents on Dll4 expression and leader cell formation. Yellow dotted lines indicate the leading edges. Images are representative from three independent experiments. Scale bars, 100 μm. (d) Density of Dll4-expressing leader cells at the leading edges. Data are expressed as mean±s.e.m. (n=3).