Skip to main content
. 2014 Dec 4;10(12):e1004847. doi: 10.1371/journal.pgen.1004847

Figure 4. Condensins I and II differentially contribute to NSC divisions and survival.

Figure 4

(A) Frozen sections of embryonic brains at E16.5 were immunolabeled with antibodies against SOX2 and Act-Casp3 (upper panels), antibodies against SOX2 and p53 (middle panels) or antibodies against SOX2 and 53BP1 (lower panels). The insets show close-ups of 53BP1-positive cells observed in cKO mice. The data shown are from a single representative experiment out of three repeats. Sections from three different embryos of each genotype were analyzed. Bars, 20 µm. The percentages of positive cells in the VZ were measured in the dorsal area of cortices at E16.5, and plotted in the right. Data were obtained from four independent sections from two different embryos. The bars indicate the mean and SD. *** P<0.001 (t-test with a Holm correction for multiple comparisons). (B) One hour after injecting mice at E16.5 with BrdU, frozen sections were prepared and immunolabeled with antibodies against BrdU and PAX6, an NSC marker (upper panels). Alternatively, NSCs in mitosis were visualized by H3S10ph labeling (lower panels). The data shown are from a single representative experiment out of three repeats. Sections from two different embryos of each genotype were used for BrdU incorporation assay and from three different embryos of each genotype were labeled with H3S10ph antibody. Bar, 20 µm. The percentages of BrdU-positive or mitotic cells in the PAX6-positive population were measured and plotted in the right. All data were obtained from three independent sections. The bars indicate the mean and SD. ** P<0.01, *** P<0.001 (t-test with a Holm correction for multiple comparisons). (C) Prophase and prometaphase chromosomes on the apical surface of the VZ were immunolabeled with H3S10ph antibody, and their morphologies were analyzed by Hoechst staining. A large Hoechst-dense structure observed in Ncaph2 cKO mice at prophase is shown by the arrow. Chromatin bridges in anaphase or postmitotic cells were observed only in Ncaph2 cKO mice (postmetaphase panels). Tail-like chromatin structures in postmitotic cells were immunolabeled with an antibody against 53BP1. The data shown are from a single representative experiment out of three repeats. Sections from three different embryos of each genotype were analyzed. Maximum intensity projections are shown. Bars, 5 µm. (D) Mitotic stages were determined based on chromosome morphologies, and their distributions were plotted. Data were obtained from two different embryos (at least 98 mitotic chromosomes scored). *** P<0.001 (Chi-squared test).