Fig. 8. Normal Olig2 expression in the pMN domain and absence of Nkx2.2 expression in the p3 domain of the Olig1-DTA embryo suggests that NSCs persist in the pMN domain but are absent from the p3 domain. (A-C) The numbers of pMN-derived Olig2⁺ cells (mean±s.d., left hemisection) are not significantly different in control (A) and Olig1-DTA (B) embryos. (D-I) Early expression of Olig1-Cre in the p3 domain is responsible for the absence of the Nkx2.2⁺ p3 domain throughout embryogenesis in Olig1-DTA mice. Nkx2.2 expression in the p3 domain seen in control embryos (D-F) is largely absent from Olig1-DTA embryos (G-I), but some residual expression in the pMN domain can be detected at E12.5 and E13.25 (H,I). (J,K) Normal expression of RC2 in the p3 domain (J, yellow brackets) is missing in Olig1-DTA animals (K, yellow brackets). RC2 expression in the pMN domain (J, white brace) is relatively normal in Olig1-DTA animals (K, white brace). Scale bars: in B, 50 µm for A,B; in I, 100 µm for D-I; in K, 50 µm for J,K.