Figure 3.

Chondrogenic characterization of END mice at newborn stage. (A and B) The close up views of middle ear bone (in blue box) and cartilage in craniobase (in yellow box) in Figure 2A showing increased hypertrophic chondrocytes (arrows) in wild type samples than (A’ and B’) in END mouse in Figure 2A’. (C and C’) The temporal cartilaginous tissue and (D and D’) Meckel’s cartilage were stained much stronger in wild type than in END mouse with Col 10 antibody (arrows). (E and E’) Immunohistochemistry of Sox9 in newborn wildtype cartilage was barely detectable while small number of Sox9 positive chondrocytes (arrows in insert) and perichondral cells was observed with a greater staining intensity in END cranial base. (F and F’) Immunohistochemistry of Runx2 in newborn wildtype cartilage was significantly stronger and have more positive cells (arrows in insert) while only few positive perichondral cells and chondrocytes were observed in END cranial base. Results of Sox9, Runx2, and PCNA immunohistochemistry were quantitated by average pixel numbers positive staining per 400× field. Scale bar: 100um for A, A’,B, and B’; 50um for C,C’,D,D’,E,E’,F and F’.