Fig. 4.

Jag1 activates αSMA-positive mesenchyme in the calvaria without bone overgrowth. Representative H&E histology (a) shows increased periosteal mesenchyme and improved bone matrix production 42 days post defect in the µC-Jag1 group (arrows) relative to the incomplete mineralization and fibrosis in the associated µC-Vh control (arrow). BMP2 induced supraphysiological production of bone (BN) and fatty marrow (MA), encapsulating and preserving the Gelfoam scaffold (GF). Select ROIs are zoomed adjacent to source images and marked using dashed lines. Scale bars are equal to 500 µm. αSMA-Cre^ERT2;tdTomato reporter activity is increased in the µC-Jag1 group relative to its µC-Vh control (b). Confocal scale bars are equal to 200 µm