Fig. 6.

MEF2 is expressed in mushroom body neurons, but not their neuroblast or ganglion mother cell precursors. (A) A sagittal paraffin-embedded section through the brain of a first instar larva fed BrdU immediately after hatching and then immunolabeled for BrdU (brown) and MEF2 (blue); anterior is to the left. Anti-BrdU labels the nuclei of MB neuroblasts (MB Nb) and antennal lobe neuroblast (AL Nb) and their daughter cells, including a putative ganglion mother cell (GMC, arrowhead). Highly specific anti-MEF2 labeling is apparent in cell nuclei surrounding the MB neuroblast, and more weakly staining cell nuclei are visible near the antennal lobe neuroblast (left-most arrow). (B) A first instar larval brain section immunolabeled only for MEF2 shows the absence of MEF2 in neuroblasts and a putative ganglion mother cell. At least three larvae were evaluated for each experiment.