Figure 2.

Biomechanics-driven development of cartilage from embryo to fetal stages and beyond. A, B) Progenitor cells migrate from the early mesoderm to sites of skeletogenesis (A), where they undergo precartilaginous condensations (B). C) Chondrocyte progenitors secrete cartilage-specific matrix and decrease expression of cell-cell interaction proteins. D) Proliferation continues at the subchondral growth front, while endochondral ossification occurs throughout the juvenile stages to transform cartilage into bone. E) Ends of long bones remain capped with a layer of articular cartilage throughout adulthood.