FIG 3.

Effects of Smpd3 expression on chondrocyte proliferation in fro/fro mice. (A and B) Immunostaining of a humerus section from an E15.5 WT embryo using an anti-SMPD3 antibody. High levels of SMPD3 expression are seen in the prehypertrophic region (b), while lower levels of expression are seen in the proliferating region (a) and the hypertrophic zone (c) of the growth plate. Strong Smpd3 expression was also detected in the osteoblasts (d). (B) Magnified views of the boxed areas in panel A. (C) Immunostaining of humerus sections from E16.5 WT and fro/fro embryos using an anti-BrdU antibody. P, proliferating zone; PH, prehypertrophic zone; H, hypertrophic zone; B, bone. (C1 and C2) Magnified views of the boxed areas in the proliferating zones of the humeri. (Right) Quantification of BrdU-positive nuclei shows that there is no significant difference in chondrocyte proliferation between WT and fro/fro mice.