Movie 4

EC at the outer curvature of the aortic arch express active β1 integrins at the apical surface. Mouse aortic arches were stained en face with antibodies targeting active β1 integrins (9EG7; red). EC were co-stained using anti-PECAM-1 antibodies (green) and nuclei were counterstained using DAPI (nuclei; blue). Fluorescence was measured at the outer curvature region using super-resolution confocal microscopy. A z-series stack of images was generated and represented in 3D using Imaris software. Note the presence of red signal (active β1 integrins) on the apical (upper) and basal (lower) surfaces.