Figure 3

Histological findings. Toluidine blue staining of A. Intermediate vertebrae with irregular shaped vertebral bodies and B. Fused vertebrae with ectopic bone formation and denser notochord. Remnants of the arch center are present at ventral side of the notochord (arrow). Growth zones of vertebral endplates in C. Non-deformed D. Intermediate and E. Fused vertebrae. Osteoblasts appeared more disorganized throughout the pathology (arrow). At fused stage, osteoblasts located abaxial between vertebral bodies were observed. Double staining with Alizarin red S and toluidine blue of F. Non-deformed, G. Intermediate and H. Deformed vertebrae. Ectopic bone formation and reduced (arrow) or fused (white double arrow) arch centra was prominent throughout the developing pathology. Alizarin red S staining of I. Non-deformed J. Intermediate and K. Fused vertebrae. Notochordal tissue did not stain with alizarin red S until fusion was complete (arrow). ND, non-deformed; IM, intermediated; FS, fused, nc, notochord; ns, notochordal sheath, eb, endbone; ec, ectopic bone. Scale bar = 100 μm.