Abnormal proliferation, differentiation and no obvious change in apoptosis at the coronal suture in Fgfr2+/P253Rmice. A, B) Immunohistochemical staining of BrdU shows decreased numbers and abnormal distribution of positive cells in mutants at E17.5 (arrow). C, D) ALP staining showed broad ALP domain and expansion of expression into the coronal suture of the mutants at E17.5 (arrow). E, F) Immunohistochemical staining of Runx2 shows increased expression and abnormal differentiation at the osteogenic fronts at E17.5 (arrow). G, H) In situ hybridization of osteonectin shows accelebrated bone formation in mutants at E17.5. I, J) TUNEL staining shows no clear difference in apoptosis between the mutant and wild-type at P5 (arrows). Panels A, C, E, G and I are from littermate controls. Panels B, D, F, H and J are the corresponding regions in mutant mice. (Scale bars: A-F = 50 μm).