Fig. 6. Apoptosis and cell proliferation in Ssdp1^hsk/hsk mutants. Sections showing the distribution of apoptotic (A,B) and proliferating (E,F) cells in the head region of wild-type (A,E) and Ssdp1^hsk/hsk mutant (B,F) embryos. (D) Scale bar in F, 400 µm for A,B,E,F. (C,D,G,H) Quantitation of apoptotic and proliferating cells in various tissues of wild type and Ssdp1^hsk/hsk mutants at E8.0 and E8.5. Values shown represent the means and standard errors of the percentages of the apoptotic (C,D) or proliferating (G,H) cells to total cells. Black and white bars represent wild-type and Ssdp1^hsk/hsk mutant embryos, respectively. The number above each bar indicates the number of samples analyzed. The tissues with significant differences between wild-type and mutant are indicated (^*P<0.05, ^**P<0.01). mesen, mesenchyme.