Bowman’s duct and gland development appear normal in the <i>Ascl1</i> KO OE.

<p>OE sections harvested at various ages were stained for <b>K18</b> to mark sustentacular cells and developing Bowman’s duct and gland units. In sections harvested from <b>E16.5</b> and later, examples of developing duct/gland units and gland acini are indicated by <b>arrows</b> and shown at higher magnification in insets. At <b>E12.5</b> and <b>E14.5</b>, ducts are not yet distinct. However, occasional intensely stained cells that are indicated by <b>arrowheads</b> extend toward the basal lamina, and are presumably developing ducts (<b>B)</b>. By <b>E16.5</b>, epithelial spanning ducts in the lamina propria are seen in both <b>HET</b> and <b>Ascl1 KO</b> (arrows in <b>C</b>, <b>D</b>, <b>H, I, J</b>). Insets show the duct/gland structures identified by <b>arrows</b>. Scale bar in <b>J</b> (50 µm) applies to <b>A–J</b>. Scale bar in the inset of panel <b>J</b> (25 µm) applies to all insets.