Osteogenic differentiation of bMSC isolated from fetal bone marrow. (A) Complex cell-interactions and extracellular matrix formation were observed in differentiating bMSC during a 27-Day culture period. (B) Higher (P < 0.05) levels of OC mRNA and ALPL activity were detected in differentiated bMSC at Days 16, 24 and 27 compared to untreated controls. NANOG mRNA levels increased (P < 0.05) from days 16 to 27 in differentiated mMSC. (C) CD73 mRNA expression was upregulated in untreated bMSC at Day 24 of osteogenic culture. (D) Activity of ALPL were higher (P < 0.05) in differentiated bMSC compared to control. (E) Osteogenesis was confirmed at Day 27 of culture by immunodetection of OC and (F) von Kossa staining of the matrix. Phase contrast (PC), OC and merged with DAPI for control and differentiation bMSC. Data are shown as mean ± standard errors. Superscripts (a,b,*) represent significant (P < 0.05) differences between treatment and sampling days. Bar scale: (A) 500 μm; (E) 20 μm; (F) 500 μm.