Pulsatile medioapical actomyosin network assembly correlates with apical cell area contractions. (A) High-resolution Airyscan time-lapse movie of F-actin (Lifeact::GFP) and MyoII (MyoII::mCh) taken every 30 s. Note F-actin and MyoII accumulation in nodes and filamentous structures. (B) Positive Pearson’s correlation between F-actin and MyoII in a single LC. (B′) Time-shifted Pearson’s correlation between medioapical F-actin and MyoII shows a strong positive correlation at 0 s time-shift (mean R = 0.4400, N = 15 cells from three eyes, one-sample t test: P < 0.0001). (B″) Time-shifted Pearson’s correlation between medioapical F-actin and apical cell area shows a negative correlation at a −15 s time-shift (mean R = −0.2706, N = 15 cells from three eyes, one-sample t test: P = 0.0014). (C) Negative Pearson’s correlation between MyoII intensity and apical cell area in a single LC. (C′) One sample t test shows a significant negative correlation between medioapical MyoII levels and cell area at a 0 s time-shift (mean R = −0.2190, N = 11 from three eyes, P = 0.0482). Scale bar = 3 µm.