Analysis of traction stress distribution in FAs in MEF (8.6 kPa ECM). (A) Immunolocalization of paxillin and fluorescent phalloidin staining of actin. Right panel: Zoom of boxed region on left. Proximal and distal directions are marked.
(B) Images of eGFP-paxillin (top left, top right: zoomed image of the boxed region) and corresponding maps of reconstructed traction stresses on the ECM with positions of FA outlined in black (bottom left and bottom right: traction magnitude heatmaps; middle right: stress vector field overlaid on inverted contrast image of eGFP-paxillin).
(C and D) The center of the FA (position of peak eGFP-paxillin intensity) was set as the origin of the x axis, proximal and distal directions indicated. (C) Above: Stress vector field overlaid on inverted contrast image of eGFP-paxillin. Below: eGFP-paxillin intensity and traction stress as a function of distance along the FA shown above. Single-headed arrows: peak values; double-headed arrows: distance between peak values. (D) Histogram of the position of peak traction within single FAs, with number of FAs with peak traction stress located in each region shown (n = 1,269). Grey rectangle highlights the values that are not significantly different from the FA center.
See also Figure S1.