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

Figure 1

Sagittal sections showing CS-GAG and versican localization in the HH15 Rathke’s pouch. (a) Low magnification of d1C4 CS-GAG associated with Rathke’s pouch (small asterisk, pouch lumen). Note consistent pattern underlying diencephalon with gradual reduction in staining along pouch roof (small arrowhead to small arrow). (b) TC2 CS-GAG shows strong localization along the entire pouch roof and in the ECM of the distal half of the pouch floor adjacent to Seessel’s pouch (sp) endoderm. (c) Versican CSPG (vs) shows a pattern like that of TC2. (d) Phase contrast image of (b) and (c) showing relationship of Rathke’s pouch to neuroectoderm of the diencephalon (di) and Seessel’s pouch. (e) Higher magnification image of TC2 antigen localization. Note reduced staining in ECM along distal tip of Rathke’s pouch (large arrow). (f) Versican shows localization like that of TC2. (g) Overlay of versican and TC2 double labeled specimen shows colocalization of immunoreactivity. Note strong signal in ECM separating Rathke’s from Seessel’s pouch (large arrowhead). (h) Phase contrast image of (e–g). (i) Higher magnification of d1C4 CS-GAG shows attenuation of staining along the roof of Rathke’s pouch. Note intercellular staining of pouch epithelium of roof. (j) Perlecan (pl) demarcates basement membrane associated with Rathke’s pouch (small arrowhead). Note gaps in basement membrane structure along pouch floor and tip (large asterisks). (k) Laminin (lm) localization in the basement membrane of Rathke’s pouch also showing interruptions in pouch floor and tip. (l) Representative immunohistochemical control (contr.) showing little or no specific immunoreactivity. Scale bar in (d) =100 μm (a–d); (h) =50 μm (e–l).

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