Fig. 5. Final epidermal zippering during DC occurs at multiple independent points along the A–P axis in both WT and after Tc-zen1^RNAi.

(A–B) WT, (C) Tc-zen1^RNAi. (A–C) Confocal projections of late DC, illustrating the transverse F-Actin fibers of the epidermis and the amniotic midline puncta of apical F-Actin and pycnotic (bright, condensed) nuclei (A,C), and final DC occurring simultaneously at several positions along the A–P axis (B,C). Two successive DC stages are shown for WT (A,B), while all features are shown in the single Tc-zen1^RNAi embryo (C). See supplementary material Table S1 for numerical characterization of these features. Labeling indicates: segmental boundaries (vertical lines), the cardioblast cell rows (arrows), and scalloped maxima (arrowheads). The subsurface cardioblasts are less apparent in C3 due to projection of a thinner confocal stack than in A,B. In whole dorsum views (letter-prime panels), regions of interest are indicated by dashed grey boxes. All views are dorsal, with anterior left. Abbreviations as in previous figures. Scale bars: 20 µm.