Figure 4

Persistent buccohypophyseal canal in Gas1^-/-mutants. (a, b) Control and mutant skeletal preparations at P0 using Alcian blue and Alizarine red showing a clearly defined bony midline defect (white arrow) in the basisphenoid. (c, d) Control and mutant frontal sections stained with hematoxylin-eosin showing the bony defect in the basisphenoid bone and the modification of the position of the anterior lobe of the pituitary gland in mutant (apg, black arrow); the anterior lobe of the pituitary gland is located directly under the oral epithelium of the pharynx. apg, anterior lobe of the pituitary gland; bo: basioccipital bone; bs, basisphenoid bone; dc, diencephalon; pl, palatine bone; px, pharynx; pi, posterior lobe of the pituitary gland; rr, residual lumen.