<p>MSCs-<i>TetR</i>/<i>Amelx</i> were cultured in growth medium (Con) or osteogenic induction medium (Os) in the presence (<b>+</b>) or absence (-) of Dox for 21 days. (<b>a</b>) The expression of osteogenic marker genes (<i>Runx2</i>, <i>osterix</i>, <i>osteocalcin</i>, <i>BSP</i>, and <i>osteopontin</i>) was examined by RT-PCR analysis. <i>GAPDH</i> was used as an internal control. Quantitative real-time RT-PCR analysis was performed to examine expression of <i>osterix</i> (<b>b</b>), <i>type I collagen</i> (<b>c</b>), <i>BSP</i> (<b>d</b>), and <i>DMP1</i> (<b>e</b>) genes. <i>GAPDH</i> was used as an internal control. Significant differences (*<i>P</i><0.01: ANOVA with Tukey’s multiple comparison test: n = 3) are shown.</p
