Fig. 9. VEGF expression is reduced in the hypertrophic zones of Ctgf mutant growth plates. (A) VEGF immunostaining is reduced in the hypertrophic zones of newborn Ctgf mutants. (B) Semi-quantitative RT-PCR analysis of Vegf and Runx2 expression. Representative data from a single Ctgf mutant and wild-type littermate at E14.5 and at E17.5 is shown. The triangular bars above the photograph of the gel represent increasing numbers of amplification cycles (see Materials and Methods). Expression of Runx2 and Vegf was normalized to Gapdh in each reaction. (C) Expression of Runx2 and Vegf in Ctgf mutants relative to wild-type littermates. Data are from five pairs of Ctgf mutants and wild-type littermates. Expression of Runx2 is not altered in mutants at E14.5 or E17.5. Vegf transcripts are present at indistinguishable levels in Ctgf mutants and wild-type littermates at E14.5, but at reduced levels in mutants at E17.5; the upper and lower bands correspond to the 165 and 120 Vegf isoforms, respectively. *P<0.05. H, hypertrophic zone.