Pulse analysis of Sdk::GFP in Rac1. N17 and MLCK.ct-expressing eyes compared with WT (corresponds to Fig. 6). (A and C) A trace of Sdk::GFP levels relative to contact length at vertices at a developmental stage equivalent to 28 h APF in eyes expressing dominant-negative Rac1.N17 (A) and constitutively active MLCK.ct (C). (B and D) Correlation of Sdk::GFP levels at individual contacts relative to contact lengths in Rac1.N17 (r = −0.01; B) and MLCK.ct eyes (r = −0.22; D). (E) Paired comparisons of relative levels of Sdk::GFP at the different phases of contact pulsing in WT eyes. All statistics performed are Wilcoxon tests. Minimal length: P = 0.0929, n = 39 pairs from 17 contacts in 3 eyes; maximal length: P = 0.0229, n = 36 pairs from 17 contacts in 3 eyes; contraction: P = 0.0063, n = 30 pairs from 17 contacts in 3 eyes; expansion: P = 0.0105, n = 32 pairs from 16 contacts in 3 eyes; expansion and contraction: P = 0.0002, n = 31 pairs from 17 contacts in 3 eyes. (F) Paired comparisons of relative levels of Sdk at different time points in pulses in Rac1.N17-expressing eyes. All statistics performed are Wilcoxon tests. Minimal length: P = 0.0166, n = 37 pairs from 22 contacts in 5 eyes; maximal length: P = 0.0436, n = 44 pairs from 23 contacts in 5 eyes; contraction: P > 0.9999, n = 25 pairs from 18 contacts in 5 eyes; expansion: P = 0.9193, n = 34 pairs from 23 contacts in 5 eyes; expansion and contraction: P = 0.3786, n = 24 pairs from 19 contacts in 5 eyes. (G) Paired comparisons of relative levels of Sdk at different time points in pulses in MLCK.ct-expressing eyes. All statistics performed are Wilcoxon tests. Minimal length: P = 0.2129, n = 30 pairs from 12 contacts in 2 eyes; maximal length: P = 0.3364, n = 34 pairs from 12 contacts in 2 eyes; contraction: P = 0.8368, n = 26 pairs from 11 contacts in 2 eyes; expansion: P = 0.7442, n = 22 pairs from 12 contacts in 2 eyes; expansion and contraction: P = 0.3632, n = 26 pairs from 11 contacts in 2 eyes.