Files in this Data Supplement:

• Supplemental Materials (PDF)
• Video 2 -
  Lateral view of junction movement along apical-basal axis in ventral mesodermal cells. Maximum projection of the resliced stacks from Video 1. Apical-basal dimension is 6 µm. Images were taken at 5-s intervals using an SP5 laser-scanning confocal microscope (Leica).
• ImageJ plugins ROI_coordinates and 3D_Tile (Zipped files)
• Video 3 -
  Examples of single junction cluster that directly moves apically or shrinks along the apical-basal axis and of two clusters that fuse. Wild-type embryos expressing ubi-ECad::GFP were imaged from the apical surface of the ventral cells to 6 µm deep at 0.5-µm increments, and the tracked clusters were 3D reconstructed at each time point. Images were acquired every 5 s using an SP5 laser-scanning confocal microscope (Leica).
• Video 1 -
  Adherens junctions (E-Cad::GFP) in a wild-type embryo during apical constriction. A stack of images was taken from the apical surface of the ventral cells to 6 µm deep at 0.5-µm increments. Shown images are projection of two consecutive optical slices. At the beginning, junctions most reside at 3- to 4-µm slices. As the apical constriction progress, junctions first move into 2-µm position and then move into 1-µm position while disappearing from the more basal positions. Images were taken at 5-s intervals using an SP5 laser-scanning confocal microscope (Leica).