(A and B) Cerebral cortices dissected from E14.5 embryos (n=4 mice per genotype) were assessed by neurosphere assays. Quantification of total numbers of primary (1° NS), secondary (2° NS), and tertiary (3° NS) neurospheres (A) and proliferation of cells in primary neurospheres (B). (C) Lateral ventricular walls dissected from newborn pups (n=4 mice per genotype) were processed for ependymal cell differentiation assays and stained with acetyl α-tubulin to mark cilia. Scale bar, 50 μm. (D) Scanning electron microscopy showing ependymal cells in brains dissected from 1–2 month-old mice (n=3 mice per genotype) of the indicated genotypes. Scale bar, 10 μm. (E) Immunoblot showing phosphorylated AKT (p-AKT), phosphorylated ERK (p-ERK), and phosphorylated STAT3 (p-STAT3) in neurosphere cells generated from mice of the indicated genotypes (n=3 mice per genotype) and treated with CNTF. Densitometric data of phosphoproteins (normalized to the respective total proteins) are summarized in Fig. S8D. Assays in all panels were performed in 3 independent experiments. Data are presented as mean±S.D. of biological replicates. Representative images are shown.