Fig. 6. Developmental expression in the OB of oligodendrocyte lineage early markers. (A-F) Adjacent sagittal cryosections of E14.5 (A,D), E16.5 (B,E) and coronal cryosections of P3 (C,F) mouse OB were hybridized with either Olig1/2 (A-C) or Pdgfra (D-F) DIG-antisense riboprobes. (G-K) Sagittal (G-J) and coronal (K) vibratome sections of E14.5 (G,H), E17.5 (I,J) or P3 (K) plp-sh ble-lacZ OBs were treated for histoenzymatic detection of ß-gal activity (bluo-gal). Higher magnifications show that ß-gal⁺ cells have a unipolar morphology at E14.5 (H), and are often bipolar at E17.5 (J). At all ages examined, ß-gal⁺ cells are present in the ventricular layer. By contrast, only occasional Olig1/2- and Pdgfra-expressing cells are seen in the ventricular layer at E16.5, and none at E14.5 or P3. Scale bar: 260 µm in A-G,I,K; 80 µm in H; 20 µm in J.