Cynthia Shao

Osteoclasts are multinuclear cells derived from myeloid lineage progenitors responsible for bone resorption. Osteoclast activity within craniofacial bones facilitates critical developmental processes such as tooth eruption and skull modeling. Recent lineage tracing experiments in mice demonstrate that proper tooth eruption and skull formation requires embryonic, but not adult myeloid cells. These data suggest fundamental differences between adult bone marrow-derived as compared to embryonic-derived tissue resident osteoclast progenitor cell populations; however, we lack essential knowledge about the osteoclast progenitors found in the marrow of craniofacial bones. While recent studies suggest unique molecular signatures of mineral resorbing cells within different skeletal sites, the bulk of our knowledge and understanding of osteoclast progenitors is derived from long bones. Moreover, we completely lack transcriptomic data describing craniofacial-derived osteoclast progenitors. Osteoclasts differentiated from bone marrow of the mandible are significantly larger and have increased expression of osteoclast genes compared to osteoclasts derived from the bone marrow in the femur. Cd11b+ cells containing osteoclast precursors were isolated from mandible and femur derived bone marrow and single cell RNA sequencing of the cells was performed by the UMN Genomics Center.