Figure 4

Motor neurons progress in their program of specification while remaining in the cell cycle. (a-k) Co-immunodetection of Islet1/2 (a-i, green) or MNR2 (j,k, green) with P-H3 (red). (a,b) Maximum projections; the electroporated side is on the left. (c) Single optical section showing a high magnification view at the level of the cell marked with an arrow in (a,b). (d-g) Orthogonal sections along the cell marked with an arrow in (c). (h-k) Single optical sections taken with a 63× objective. Dotted lines mark the limit of the mitotic transgenic cell. (l-q) Co-immunodetection of BrdU (red) and Islet1/2 (green). All the pictures are single optical sections. (n-q) Orthogonal projections along the cell marked with an arrow in (m).