Discrete stages within the osteogenic lineage are revealed by alterations in the cell surface architecture of embryonic bone cells.

Specific markers for cells of the osteogenic lineage would be valuable in studies on the differentiation and maintenance of skeletal tissue. In order to better characterize the lineage of cells responsible for the formation and remodeling of bone, we immunized mice with a heterogeneous population of chick embryonic bone cells and subsequently generated and selected for monoclonal antibodies against cell surface determinants. We report here on the generation of three cell lines, SB-1, SB-2, and SB-3, which each secrete a unique antibody against a subset of differentiating osteogenic cells. Differences in immunoreactivity of osteogenic cells at precise stages of embryonic tibia development suggest the existence of an osteogenic cell lineage which is characterized by a series of discrete functional cell states progressing from osteoprogenitor cell to secretory osteoblast.