FIG 11.

Analyses of chondrocyte apoptosis in Smpd3^flox/flox; Osx-Cre and Smpd3^flox/flox; Col2a1-Cre mice. (A) Immunofluorescence analysis of E15.5 Smpd3^flox/flox, Smpd3^flox/flox; Osx-Cre, and Smpd3^flox/flox; Col2a1-Cre humerus sections using an anti-type X collagen antibody. The nuclei were stained with Hoechst stain. Magnified views of the boxed areas in the upper panels are shown in the lower panels (Hoechst stain only). The numbers indicate the percentage of nuclei with ring-shaped/collapsed chromatin, which are considered to be in the early stage of the apoptotic cycle. (B) TUNEL-positive cells within an assigned area in the growth plates of Smpd3^flox/flox; Col2a1-Cre humerus samples were quantified (n = 4). No apoptotic nuclei were detected in Smpd3^flox/flox; Osx-Cre humerus samples. Error bars represent standard deviations. **, P < 0.01.