Fig. 3. Axons of different classes of da neurons form a laminar pattern. (A) Dorsal view of axon scaffold in ppk-Gal4, UAS-mCD8::GFP ventral nerve cord. A strongly labeled set of axons (arrow in transverse section `1') is flanked by a weakly labeled set of terminals (arrowheads). Transverse section `2' shows the thickened clumps of axons at each segment. (B) FLP-out analysis shows that class III axons (arrowheads) terminate immediately lateral to the scaffold of class IV axons (arrows). Top is dorsal view, bottom is transverse section. Notice that some class IV axons show expression of mCD8::GFP due to FLP-out and, thus, the left portion of the CNS contains marked class III and IV neurons. (C) Image of CNS labeled with mCD8 (green) and Fas II (magenta). Section (yellow) shows the class III axon of v'pda (arrowhead) terminating just medial to the class II axon of ldaA (arrow). (D) FLP-out clones made with ppk-eGFP in the background to label class IV axons. Arrows indicate the class II axon. The ppk-eGFP scaffold is marked (IV). Notice that the class II axon terminates lateral to the class IV scaffold (arrowhead) and all other da axons (which are labeled by CD2). (E) Relative terminal positions of class II, III and IV neurons. The cell body position is indicated along with the class of the neuron. Genotypes: (B) hsFLP/+; ppk-Gal4/ppk-Gal4; UAS>CD2>mCD8::GFP/+; (C) hsFLP/+; Gal4^109(2)80/+; UAS>CD2>mCD8::GFP/+. (D) hsFLP/+; Gal4^109(2)80/+; UAS>CD2>mCD8::GFP/ppk-eGFP; (E) tubP-Gal80, hsFLP, FRT19A/yw FRT19A; Gal4^109(2)80, UAS-mCD8::GFP/+. Scale bars: 25 µm. D, dorsal; L, lateral; V, ventral; V', ventral'.