Fibrous periosteum repairs bone fracture and maintains the healed bone throughout mouse adulthood.

Bone is regarded as one of few tissues that heals without fibrous scar. The outer layer of the periosteum is covered with fibrous tissue, whose function in bone formation is unknown. We herein developed a system to distinguish the fate of fibrous-layer periosteal cells (FL-PCs) from the skeletal stem/progenitor cells (SSPCs) in the cambium-layer periosteum and bone marrow in mice.

Tracing the skeletal progenitor transition during postnatal bone formation.

Multiple distinct types of skeletal progenitors have been shown to contribute to endochondral bone development and maintenance. However, the division of labor and hierarchical relationship between different progenitor populations remain undetermined. Here we developed dual-recombinase fate-mapping systems to capture the skeletal progenitor transition during postnatal bone formation.