Tension affects Sdk dynamic localization to vertices. (Refers to Table S2 and Video 5.) (A–D) Sdk::GFP dynamics relative to actin and contact length in eyes expressing dominant-negative Rac1.N17 (A and B) and constitutively active MLCK.ct (C and D) compared with WT (E and E′) at 28 h APF. (A and C) Snapshots of a dynamic contact from a time-lapse video. (A′ and C′) Kymographs of the LC–LC contacts shown above. The regular patterns of expansion and contraction seen in WT are disrupted. (B and D–E′) Pearson correlation plots between Sdk levels at vertices and contact length in Rac1.N17 (B), MLCK.ct (D) and WT (E and E′) from four eyes (E) or a single eye (E′). (F) The mean peak correlation for WT contacts is significantly stronger than the correlation at the same time-shift for Rac1.N17 and MLCK.ct contacts (ANOVA, P = 0.0018; Dunn’s multiple comparisons test; *, P < 0.05; **, P < 0.01). Scale bar, 5 μm.