Fig. 6.

Downregulation of N-cadherin expression correlates with the ability of cells to leave Rathke’s pouch. Sagittal sections of e13.5 embryos were stained via immunohistochemistry for E- and N-cadherin and then the images were merged. In the wildtype pituitary, E-cadherin is dispersed throughout Rathke’s pouch and the anterior lobe (A) while N-cadherin is concentrated along the lumen of Rathke’s pouch except for the ventral area where the anterior lobe (AL) is forming (B, arrowheads mark boundaries of N-cadherin concentration along lumen). The boxes in BE, H, and K correspond to magnified images C, F, I, and L. These images were merged and viewed at higher magnification to show the dorsal aspect of the pouch with N-cadherin concentration and the ventral aspect with only E-cadherin (C). In the Hes1 mutant E-cadherin is dispersed throughout the pouch and anterior lobe (D) while N-cadherin is concentrated along the lumen of the dorsal half of the pouch (E, arrowheads). In the merged image of the Hes1 mutant it is clear that the ventral half of the pouch is void of N-cadherin concentration. The Prop1 mutant contains E-cadherin dispersed throughout the pituitary with areas of concentration along the lumen in the ventral part of the pouch (G). Nearly all of the lumen of Rathke’s Pouch is lined with N-cadherin except for the small area where cells are exiting the pouch for the anterior lobe (H, arrowheads). E-cadherin is dispersed throughout the pouch in the double mutant (J). N-cadherin lines the dorsal half of the lumen of Rathke’s pouch and is absent along the ventral half where the anterior lobe is forming (K, arrowheads). In the merged image of J and K it is clear that there is no N-cadherin concentration along the ventral half of the double mutant Rathke’s pouch (L). n=3 Magnification: 200X (A-H) 640X (I-L), scale bars are 25 μm