Fig. 4. DRL expression in the Drosophila stage 16 embryonic brain. (A,D) Confocal reconstructions of the same brain, A being dorsal to D. (B,C,E,F) Double-channel images derived from A and D. In the stage 16 wild-type embryonic brain, two commissural bundles express the DRL protein (red), one located posteriorly and slightly dorsally (A,B,C), the other being in the anterior part of the commissure (D,E,F). These bundles do not express the FASII marker (blue, C and F) and are HRP-positive (green, B and E), confirming their neuronal identity. (G-I) The LIO (red) pattern relative to the embryonic MBs (green GAL4-OK107 line), going from a dorsal to a ventral view; no colocalization is observed. Scale bar: 10 µm.