Expression data of PDGFRa- and PDGFRa+ mesenchymal stem cells isolated  from mouse periosteum
The outer coverings of the skeleton, or periosteum, are arranged in concentric layers and act as a reservoir for tissue specific bone progenitors.  Cellular heterogeneity within this tissue depot is increasingly recognized.  Here, Pdgfra reporter animals were used to highlight a subset of periosteal progenitor cells with high osteogenic potential.  Pdgfra+ periosteal progenitor cells enhanced osteogenic differentiation in vitro and improved fracture healing and bone regeneration in vivo.  Depletion of Pdgfra-expressing progenitor cells interferes with cortical appositional bone, periosteal bone formation in response to mechanical load, and during fracture repair.  Pdgfra+ periosteal progenitors give rise to Nestin+ periosteal cells overtime, after fracture and upon transplantation. Overall design: 4 Total samples were analyzed. The cells in each sample were isolated from 3-6 male mice.  Two samples of PDGFRa+ FACS-sorted cells were compared to two samples of PDGFRa- cells.