Long bone growth is impeded in A10ΔEC mice. (A,B) Radiographs of the hind limb of an A10ΔEC mouse (A) revealed a substantially shorter femur than in a control mouse (B). (C-D) Quantification showed significant reduction in the length of the femur and tibia in A10ΔEC mice compared with controls (C; femur length, A10ΔEC:10.9 mm ± 0.5 n = 6; controls: 14.7 mm ± 0.3 n = 6; D; tibia length, A10ΔEC: 15.9 mm ± 0.3 n = 6; controls: 17.4 mm ± 0.2 n = 6,). (E-J) H&E staining of femoral condyles from A10ΔEC (E,G,I) or control mice (F,H,J) revealed an abnormal growth plate (arrows in panel E), disturbed trabecular bone architecture (asterisk in E), abnormally oriented and enlarged vessels (arrow in panel G) and aberrant spindle shaped stromal cells (arrowhead in panel I) in A10ΔEC specimens compared with the normal growth plate (arrows in panel F), trabecular bone (asterisk in panel F), vessels (arrow in panel H) and compact hematopoietic cells within the marrow compartment (arrows in I,J) in controls. Data show mean ± SEM. Scale bars in panels A-B: 8 mm; E-F: 500 μm; G-H: 100 μm; I-J: 20 μm.