Figure 1

Immunohistochemical staining of human embryonic craniofacial sections. (A) During elevation (6th-8th week embryos) of the palatal shelves osteopontin (SPP1) protein is present in the palatal mesenchyme. (B) Chemokine receptor 4 (CXCR4) was present in the epithelial lining of the oronasal cavity and the palatal shelves. (C) During fusion (9th-11th week fetuses) of the palatal shelves SPP1 is present in the palatal mesenchyme and (D) CXCR4 is present in the epithelium of the oronasal cavity, including the medial edge epithelium, where the palatal shelves meet and fuse. (E) Serglycin (PRG1) protein expression was not present in the early gestational age (6-8 weeks), but became apparent during palatal fusion in the epithelial lining of the oronasal cavity and in the medial edge epithelium. Black color indicates expression. (Hematoxylin-eosin or toluidine blue staining, primary magnification ×1.25).