Fig. 3. Tissue structure during DC in the epidermis and amnion.

(A–E) WT, (F–I) Tc-zen1^RNAi. (A–I) Confocal projections of early (A,C,D,G,H), and mid (B,E,F,I) DC illustrate several shared features between WT and Tc-zen1^RNAi DC: the straggling organization of the dorsal-most epidermal cells (A1,A2–A2‴,B,F: starred cells), the more lateral F-actin-enriched but unpolarized cardioblast cell row (A3 [partial projection], E,E′: arrows, curly brackets), and amniotic cell elongation around the serosa or amniotic crease (A1,A2,C,G: arrows). In contrast, amniotic F-actin fiber organization differs (D,I: arrows). For comparison, the subsurface cardioblast cell row is superimposed in A1,A2,B,F (paired thin lines). Dashed boxes in A1,A2′,E show enlargements in A2–A3,A2‴,E′, respectively. Horizontal white lines in A2 demarcate segmental boundaries. In the A2‴ schematic and B,F, indicative cells are colored for the lateral epidermis (cyan), dorsal-most epidermis (grey), and amnion (orange). Greater epidermal cell elongation in F than B reflects a slightly older embryo, not a phenotypic difference. The Tc-zen1^RNAi amniotic crease is labeled with arrowheads (G,H). The curly bracket in I marks the anterior ball structure (see also Fig. 1L). Images are oriented with anterior up and dorsal/medial right. Staining reagents are as indicated (Arm1 is anti-Tc-Arm1). For additional Tc-zen1^RNAi images, see supplementary material Fig. S2. Abbreviations as in previous figures. Panels C and D show the same two embryos as in Fig. 2C and Fig. 1C, respectively. Scale bars: 20 µm (A,E), 10 µm (A2–A2″,B,E′,F), 5 µm (A2‴), and 100 µm (shown in H for C,D,G–I).