Fig. 3.
Confocal microscopy to compare GAL4-mediated expression visualized with the reporter GFP and with PDF. The spatial distribution of GAL4-driven GFP and PDF was often different. In theelav-gal4; UAS-gfp line, GFP was prominently revealed in the photoreceptor cells (A, the arrow points to their axonal terminals in the first optic ganglion) and other cells in the optic lobe (OL), whereas no PDF was found in these cells (B). The only PDF labeling present in the optic lobes stemmed from the processes of the LNv that formed a varicose network (arrow in B) on the surface of the medulla. Similarly, no PDF was found in ring neurons of the ellipsoid body (ebo), although these cells strongly expressed GFP (arrowheads in C). Even the spatial distribution of GFP and PDF in the same neuron was often different: GFP labeling was found in the Kenyon cells (D, arrowheads) and their corresponding dendrites in the Calyx (Ca) of the mushroom body. However, ectopic PDF was only revealed in the α-, β-, and γ-lobes and the pedunculus (Ped) of the mushroom bodies (E). To test whether GAL4-mediated expression was present in the LNvs, double-labeling with anti-PDH was performed on the relevant gal4-lines wherebygal4 expression was visualized with GFP. In the lineMz1525-gal4; UAS-gfp, GAL4-mediated GFP (F) was found in all PDF-labeled LNvs (G) as revealed by superposition of GFP and PDF labeling (H). Scale bars (shown in A) A,B, 50 μm; (shown in D)C, D, E, 50 μm; (shown in F) F–H, 20 μm.