Periosteal cells were isolated from young chicks, introduced into cell culture, subcultured,
and then inoculated into athymic, nude mice to test the in vivo osteochondrogenic potential
of cultured periosteal cells. In monolayer cultures, the adherent periosteal cells showed
fibroblast like morphology and overtly expressed neither osteogenic nor chondrogenic
phenotypes. Cultured cells inoculated heterotopically into nude mice eventually gave rise to
bone tissue at the subcutaneous injection site. The process of bone formation occurred …