Movie 4

Traction force relaxation upon central fibre ablation.
This movie shows the relaxation of the traction force field of RPE1 cells plated on crossbow-shaped micropattern on poly-acrylamide hydrogels. Cells were expressing Lifeact-GFP in order to visualize the actin network (gray). Cells were treated with a control siRNA (siCTR, top) or siRNAs against α-actinin 1 and 4 (siACTN, bottom). Images were taken every 5 seconds. Green arrows show the displacement field of the beads embedded in the acrylamide gels between two consecutive images. The red arrows on the second image show the ablated region. As a consequence, the relaxation field is much higher on this image and differentially orientated in control cells and those in which α-actinin has been down regulated.