Fig. 3. Asymmetric protein localization along the apical-basal axis in NGB 6-4T and GB 6-4A. (A) Lateral view of stage 10 embryos; apical is upwards; basal is downwards; anterior is towards the left. NGB 6-4T (6-4T) and GB 6-4A (6-4A) were identified as described in Fig. 1 and the Materials and Methods. DNA was labeled with anti-phosphohistone H3. Inscuteable (Insc) forms an apical crescent in mitotic NGB 6-4T (n=7) and GB 6-4A (n=8) and is partitioned to the apical precursor after cytokinesis. Miranda (Mir), Numb and Prospero (Pros) form basal crescents in mitotic NGB 6-4T and GB 6-4A, and are partitioned into the basal G daughter cells in both lineages after cell division (n>13 for Mir and Pros; n>6 for Numb). The arrow in the 6-4T Mir panel shows and example of a mitotic NGB 7-4 during a glia-producing division; we find these divisions to also occur along the apical-basal axis. (B) Summary of Prospero protein (Pros), gcm mRNA and Gcm protein localization in the NGB 6-4T lineage. See text for details.