Fig. 2.

Lower mRNA expression levels of several bone-specific marker proteins in the SmoM2 mutant relative to the control. Primary calvarial cells were isolated from SmoM2;OCN-Cre mutant or controls at the indicated postnatal ages (2–5 weeks), and the expression patterns of bone-related genes were determined by real time RT-PCR. The results show the mean ± SD from three independent experiments. ^*P < 0.05, ^**P < 0.01, and ^***P < 0.001 vs. the experiments. NS, not significant.