Relative expression of marker genes in murine bone marrow (BM; A), perirenal adipose tissue (PAT; B), and mediastinal stromal tissue (MST; C) derived progenitor cells during osteogenic (A1, B1, C1) and adipogenic (A3, B3, C3) differentiation using the "mesenchymal microsphere" (MMS) protocol. Expression of bone sialoprotein (BSP) and osteopontin (OP) is demonstrated by immunostaining in MMS (18 d; A2, B2, C2). Nuclei are stained with DAPI (blue). Mean values ± SEM derived from independent samples per experimental group (n = 3) are shown. Bar = 100 μm.