Figure 6.

In situ hybridization, using a collagenase riboprobe, of calvarial bone from +/+ and r/r mice injected subcutaneously over the hemicalvariae with vehicle or PTH. The outer (subcutaneous) side is shown. Sections were hybridized with the antisense collagenase riboprobe and were visualized using bright field (top) and dark field (bottom). Arrows indicate the periosteum. No hybridization with the collagenase riboprobe was detected in the periosteum in calvariae from vehicle-treated +/+ mice or vehicle-treated r/r mice. In calvariae from both +/+ and r/r mice, levels of collagenase mRNA in periosteal osteoblasts were markedly increased after PTH injection. No signal was observed in samples hybridized with the collagenase sense riboprobe (not shown). Scale bar, 0.05 mm.