The Wnt/β-Catenin Pathway Interacts Differentially with PTHrP Signaling to Control Chondrocyte Hypertrophy and Final Maturation
Figure 2
Analysis of chondrocyte hypertrophy in β-catenin and Smo mutant embryos.
(A) Skeletal preparation of 18.5 dpc embryos. Mineralization (stained by Alizarin red) in the Catnbc/c; Smoc/c; Col2a1-Cre double mutant embryo was more advanced than that in the Catnbc/c; Col2a1-Cre mutant embryo, but less advanced than that in the Smoc/c; Col2a1-Cre mutant embryo. (B) Sections of the developing distal tibia at 15.5 dpc were examined by in situ hybridization with PTHrP probes. PTHrP expression was slightly reduced only in the periarticular chondrocytes in Catnbc/c; Col2a1-Cre mutant embryos compared to that in wild type embryos. Catnbc/c; Smoc/c; Col2a1-Cre and Smoc/c; Col2a1-Cre embryos have similar expression of PTHrP. (C) Safranin O staining and Col10a1 expression in the developing humerus at 15.5 dpc. Non-hypertrophic chondrocyte region (white line) was expanded in the Catnbc/c; Col2a1-Cre mutant, but reduced in the Smoc/c; Col2a1-Cre mutant embryo, compared that in the wild type control. Chondrocyte hypertrophy in the Catnbc/c; Smoc/c; Col2a1-Cre double mutant embryo was delayed than that in the Smoc/c; Col2a1-Cre mutant embryo, but accelerated than that in the Catnbc/c; Col2a1-Cre mutant embryo.