Heterogeneous Expression of Chondroitin Sulfate Glycosaminoglycans and Versican Proteoglycan during Early Development of Rathke’s Pouch

Figure 5

CS-GAG and versican localization in sagittal sections of Rathke’s pouch at HH28. Note presence of cephalic (large asterisk) and caudal (small asterisk in lumen) lobes of the pars distalis. (a) TC2 CS-GAG is localized in mesenchyme and along the roof of the caudal lobe (arrow) and underneath the infundibulum (in, small arrowhead). Intercellular staining of roof cells of caudal lobe is also evident. Staining around cephalic lobe appears largely mesenchyme associated. Weak reactivity between cephalic lobe cells is seen as is weak staining between the narrowed Rathke’s pouch connection to oral cavity (large arrowhead). (b) Phase contrast image of (a). di: diencephalon. (c) Versican (vs) is localized in diencephalon and is associated with surrounding head mesenchyme. Little staining is seen in roof of caudal lobe (arrow) although overlap with TC2 is noted along its distal floor extending toward infundibulum (small arrowhead). Weak reactivity between epithelia of the caudal lobe is seen. Note little staining associated with proximal connection of Rathke’s pouch with oral cavity (large arrowhead). (d) TC2 antigen and versican double label shows limited colocalization associated with Rathke’s pouch (arrow, arrowheads) but can clearly be seen in surrounding mesoderm. (e) d1C4 CS-GAG is localized within and beneath the diencephalon and along roof of the caudal lobe (arrow). Note reduced staining underlying infundibulum and distal floor of caudal lobe (small arrowhead). Weak staining is noted around cells of the cephalic lobe. Slight staining of epithelia and basement membrane underlying distal connection to oral cavity is present (large arrowhead). (f) Perlecan (pl) demarcates basement membrane surrounding the pituitary rudiment. Note distinct basement membrane structures associated with diencephalon and caudal lobe (arrow, small arrowhead) and fusion at site of contact with infundibulum. Reduced perlecan expression can be seen associated with the roof side connection to oral cavity (large arrowhead). Scale bar in (b) =100 μm (a–f).

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