Fig. 4. Gene expression profile of BMSSCs in vivo and following differentiation in vitro. RT-PCR analysis of gene expression in STRO-1^BRIGHT/VCAM-1⁺-purified BMSSCS isolated directly from marrow aspirates (1), and when cultured in regular growth medium (2) or medium inductive for either for bone, fat or cartilage development (3) as described in Materials and Methods. The expression of a range of markers characteristic of each tissue is shown. Bone: transcription factors CBFA1 and osterix (OSX), collagen type I (COL-1), osteopontin (OPN), osteocalcin (OCN) and parathyroid hormone receptor (PTH-R). Fat: lipoprotein lipase (LPL), transcription factor PPAR2 and leptin. Cartilage: collagen type II (COL-II), collagen type X (COL-X) and aggrecan (AGGN). Reaction mixes were subjected to electrophoresis on a 1.5% agarose gel and visualised by ethidium bromide staining. RNA integrity was assessed by GAPDH expression.