Fig. 2

Defects in ME patterning in Pax7 ^−/− esophagi. a–r Cross sections of P0, P7, and P21 Pax7 ^+/− and Pax7 ^−/− esophagi were stained with antibodies to αSMA, SA, and DAPI. j, l The P7 and P21 Pax7 ^−/− esophagi are dilated, and skeletal muscle is replaced by smooth muscle at the mid-level region (Mid). s–u Luminal diameter at the mid region of Pax7 ^−/− esophagi is larger than that of Pax7 ^+/− esophagi at P7 and P21. Values are means ± SD, n = 3–11. v, w Cross sections of P7 Pax7 ^+/− and Pax7 ^−/− esophagi at the mid region were stained with H&E. Ep epithelium, MM muscularis mucosa, ME muscularis externa. The black horizontal bars indicate the width of the ME; the asterisks indicate the lumens. x Quantification of the width of the ME, as shown in (v and w). Values are means ± SD, n = 3. Bars: (a–r) 0.2 mm, (v, w) 50 μm. **P < 0.01; ***P < 0.001