C&E movements of the medial PSM entail multiple cell intercalation behaviors. (A) Schematic of the analyzed cell population in WT. Dorsal views. Cells leaving the analyzed layer during the recording are shown in blue; cells entering the layer are shown in red. Six cells are assigned numbers to illustrate the significant neighbor exchanges. (B–E) Schematics and frequencies of planar medial intercalation, coordinated radial/medial intercalation, radial AP intercalation, and radial ML intercalation, respectively. Medial is to the left. (F) Frequencies of the three types of radial intercalations listed in C–E in WT, kny;tri double mutants, and embryos injected with synthetic RNA encoding Xdd1. (B–F) Error bars represent the standard error. A, anterior; M, medial. *, P < 0.05; **, P < 0.005, mutant vs. WT.