Fig. 6.

mRNA and protein levels of PDGF receptor-β produced by chondrocytes in superficial and deep zones. PDGFRB mRNA level in superficial-zone chondrocytes (SZC) was 4 times higher than that in deep-zone chondrocytes (DZC), as assessed by quantitative reverse transcription-PCR (ΔCt method) (A). The protein level of PDGF receptor-β was > 4 times higher in the superficial zone than in the deep zone, as assessed by Western blot analysis (B). The blots were cropped from different parts of the same gel; and full-length gels and blots are included in the Supplementary Information. **p < 0.01, Mann-Whitney U-test