Description
Chondrocytes from extra fingers exhibited a high proliferative capacity: the cells reached to population doublings (PD) 30-35 within 4 weeks before replicative senescence. The propagated cells formed hyaline cartilage at 2 weeks after subcutaneous implantation of NOD/Scid/IL-2 receptor gamma knock out (NOG) mice, and the generated cartilage showed enchondral ossification at 8 to 12 weeks. The cartilage formation with osteogenesis depends on the number of cell division in vitro.