Distinct differences between calvarial and long bone osteocytes in cell morphologies, gene expressions and aging responses

Osteocytes are the terminally differentiated bone cells which regulate bone homeostasis. Previous studies have shown that calvarial osteocytes and femoral cortical osteocytes are derived from intramembranous and endochondral ossification, respectively. However, it is not clear if the distinct pathways could contribute to different types of osteocytes. In this study, we employed confocal structured illumination microscopy (SIM), cell lineage tracking and mRNA-seq analysis to characterize the cell origin, morphologic and transcriptomic expression of osteocytes from murine calvaria and mid-shaft femoral cortical bone. Here we concluded that ossification contributed to osteocyte morphology. Besides, osteocytes derived from different ossifications respond to aging differently.