Figure 6.

Lineage specification of mesenchymal stem cells in pellet culture at 20% pO₂. (a) Simulated – distribution after 0 and 14 days for cells expanded at 5% and 20% pO₂. Cells committed to the chondrogenic lineage are shown in magenta. The colour saturation is a marker of the differentiation level. Chondrogenic commitment is seen throughout the spheroid except of some cells at the periphery. (b) Averaged differentiation versus radial distance from the spheroid centre at day 0 (red), 2 (green), 7 (blue) and 14 (magenta). (c) Expression of the chondrogenic transcription factor SOX‐9 (red) after 14 days demonstrates the predicted chondrogenic commitment throughout the spheroid. A typical pellet of cells expanded at 20% pO₂ is shown (blue: DAPI staining).