Fig. 2. Acquisition of the epidermal growth factor receptor (EGFR – shown in red with nuclei counterstained in blue) by NSCs is delayed in tenascin C (TNC) null brains. At E12.5, note the absence of EGFR immunostaining in the TNC null mice (K/O, B), whereas EGFR is present in their heterozygous littermates (+/–, A). At later stages (E17.5, C,D; P17, E,F), similar patterns of EGFR immunolabelling are observed in homozygous and heterozygous animals. Similar results were observed in three sets of littermates. Scale bars: 100 µm in A,B; 200 µm in C,D; 80 µm in E,F.