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Fig. 6. Defective osteogenesis in Fgfr2cko mice. (A,B) H&E
stained sections of the distal tibia of P7 mice, showing the epiphyseal growth
plate. The length of the metaphysis is indicated by the double-headed arrows.
(C,D) Enlarged views showing the morphology of metaphyseal osteoblasts in the
proximal tibia. Note that osteoblasts are plump cuboidal cells in the
wild-type mouse and become atrophic and irregular in the
Fgfr2cko mouse (arrows). (E,F) Enlarged view of the boxed
regions in A and B showing the morphology of the perichondrium. The thickness
of the perichondrium is indicated by double-headed arrows. (G,H) H&E
stained sections showing the femoral diaphysis of P7 mice. The thickness of
the cortical bone plus the periosteum is indicated by double-headed arrows.
Diaphyseal lacunae occupied by active osteoblasts are indicated by arrows.
(A,C,E,G) Sections from control littermates. (B,D,F,H) Sections from the
Fgfr2cko mice. Objective magnification, (A,B) 10x;
(C-F) 40x; (G,H) 20x. bm, bone marrow; cb, cortical bone; fc,
fibroblast-like cell layer; h, hypertrophic zone; mu, muscle; op,
osteoprogenitor layer; p; proliferation zone, po, periosteum; tb, trabecular
bone.