Fig. 3.

Striated myogenesis occurs in esophagi with mechanically disrupted muscularis externa. A Sagittal section of E14.5 esophagus with a disrupted muscularis externa (arrow) but contiguity of the rostral and caudal segments after 7 days of culture shows myogenin expression on both sides of the zone of disruption (insets). The apparent dissociation to the right of the arrow (rostral) is a sectioning artifact, where a section of esophagus was positioned outside of the sectioning plane. B Myogenin expression is visible only in the subpharyngeal segment in a completely transected E14.5 esophagus after 7 days of culture, but is absent in the caudal segment (insets). Scale bars for large panels = 500 μm; scale bars for insets = 100 μm.