Branched network at linear AJs contains Arp2/3 complex. (A) Overview of a linear AJ between two pseudocolored cells. The outlined region is enlarged in B. (B and C) Distributions of Arpc2 (12 nm, red) and VE-cadherin (18 nm, yellow) immunogold largely colocalize with the junctional strip of branched actin network. The region outlined in white in B was analyzed at high magnification. Broad tangential bundles are located at a distance from the branched strip. Some oblique actin bundles and filaments joining the branched strip are highlighted in cyan. Region outlined in green is enlarged in C. Bars: (A) 5 µm; (B) 1 µm; (C) 500 nm. (D) Densities of VE-cadherin and Arpc2 immunogold per area occupied by the cytoskeleton within junctional networks and in adjacent cell regions. Error bars indicate SD; ***, P < 0.001. n = 7 PREM montages with total area of 90 µm² (25.2 µm² of junctional networks with 64.5 ± 3.3% [mean ± SD] coverage by the cytoskeleton and 64.4 µm² of adjacent regions with 33.8 ± 9.0% coverage by the cytoskeleton). Data distribution was normal by Kolmogorov–Smirnov normality test. Significance was determined by parametric Tukey–Kramer multiple comparisons test.