Figure 7

Suppressing Notch signaling abolished the upregulation of neural progenitor proliferation caused by BMP-BmpR1 inactivation (A,C) All panels are dorsal views of flat-mounted embryos at 10 hpf with the anterior on the top analyzed using in situ hybridization for sox2 expression and immunohistochemistry with phospho-histone H3 (pH3) antibody. Embryos at 8 hpf were treated with heat-shock-induced DN-BmpR1aa or treated with DHM1 for one hour. The upper panel shows bright field images and the bottom panel shows fluorescent images taken from identical embryos of the upper row; the expression of sox2 was pseudo-colored with fluorescent red and counterstained with proliferating marker pH3 (fluorescent green). (B,D) The results of in situ hybridization were confirmed by quantitative reverse transcriptase PCR (qRT-PCR) and the proliferating neural progenitors (fluorescent yellow) were subjected for cell counts (B). n, total number of embryos analyzed from three independent experiments. The percentages in each panel in (A,C) indicate the proportion of embryos displaying the same phenotype as that shown in the photographs of the total embryos examined. Quantitative data are presented as mean ± standard deviation (SD). * p < 0.05; ** p < 0.01; *** p < 0.001.