Fig. 3. Reduced bone formation in OG2-NcadC transgenic mice: histologic and histomorphometric analysis. (A) Goldner's trichrome stained, 4 µm undecalcified sections of proximal tibiae from OG2-NcadC (Tg) or wild-type (WT). Micrographs on the right are enlargements (400x) of the rectangular areas shown on the left micrographs (200x). (B) Bone volume, expressed as a percentage of total tissue volume (BV/TV) in the entire area of the bone marrow cavity 175-875 µm from the growth plates was significantly reduced in transgenic mice compared with those of wild-type controls (n=8). (C-E) OG2-NcadC mice also exhibited a significantly lower trabecular number and thickness and higher trabecular separation compared with wild-type mice. (F) Fluorescence micrograph of calcein labeling in 8 µm unstained sections of cancellous bone, showing no double labels in sections of transgenic mice bone. Accordingly (G,H), dynamic parameters of bone formation, bone formation rate/tissue volume and mineral apposition rate were significantly reduced in transgenic mice compared with wild-type littermates. (I) Four-micrometer sections of proximal tibiae were stained for tartrate resistant acid phosphatase activity and counterstained with methyl green and thionin for identification of osteoclasts (Oc) and osteoblasts (Ob). Micrographs on the right are enlargements (400x) of the rectangular areas shown on the left micrographs (200x). (J,K) The number of osteoblasts expressed as osteoblast perimeter per bone perimeter (%) was reduced in OG2-NcadC mice compared with wild-type mice. There was no significant difference in the number of osteoclasts between transgenic and wild-type animals. In all panels, asterisks denote P<0.05, t-test.