Cardiac and aortic expression of <i>CYP27B1</i>.

<p><i>Fgf-23^+/+/</i>1α-Luc<i>^+/−</i> (wt), <i>fgf-23^+/−/</i>1α-Luc<i>^+/−</i> (het) and <i>fgf-23^−/−/</i>1α-Luc<i>^+/−</i> (ko) mice were bred as described in <i>Methods.</i> Mice were sacrificed at 4 weeks of age, the heart and aorta removed and divided into two parts for determination of <i>CYP27B1</i> promoter activity in heart <b>(A),</b> and aorta <b>(B)</b>, expressed as luciferase activity per mg of tissue. Graph depicts fold change with respect to luciferase activity in <i>fgf-23^+/+/</i>1α-Luc<i>^+/−</i> mice. <i>CYP27B1</i> mRNA expression in heart <b>(C),</b> and aorta <b>(D)</b>, quantitated by real-time PCR, normalized to that of gus mRNA, and expressed as a percent relative to <i>fgf-23^+/+/</i>1α-Luc<i>^+/−</i> mice. Bars depict mean±SEM (n = 5 mice/group) *<i>P<0.05</i>, compared to <i>fgf-23^+/+/</i>1α-Luc<i>^+/−</i> mice.