DE-cad/Arm puncta cluster, reposition, and join Baz to form SAJs. (A and B) DE-cad∷GFP and Arm∷GFP puncta volumes (n = 5 embryos; apical, 12 µm). Mid and late cellularization are shown. Insets show example puncta in 3D. Arrows indicate elongated SAJs. (C) SAJ mergers/fissions are indicated by arrows. (D and E) Fluorescence intensity sums are shown. All apical 12-µm puncta versus BJs. Mid and late cellularization (n = 5 embryos) are shown. (F) Net displacement arrows of DE-cad∷GFP puncta (apical, 4 µm). Rows of two to three cells. Puncta tracked for 1 min. Mid and late cellularization are shown. (G) Apical versus basal movement (n = 878 mid and 1,000 late DE-cad∷GFP puncta, 8 embryos each). (H) Baz∷GFP puncta volumes (n = 5 embryos; apical, 12 µm). Mid and late cellularization are shown. (I) DE-cad∷GFP versus Baz∷Cherry. (top) Apical surface projection is shown. Arrows indicate central apical surface puncta. Bottom rows show single sections. Apical surface periphery and apicolateral SAJs are shown. Arrows indicate puncta. (right) Quantification is shown as the number of Baz∷mCherry puncta overlapping the 10 brightest DE-Cad∷GFP puncta per field (n = 10 embryos). Means ± SD are shown. *, P < 0.01.