Fig. 6. hb affects the number of eve-expressing neurons. Flat preparations of embryos at stage 15, dorsal view, anterior is leftwards. Horizontal square brackets, aCC and pCC; vertical square brackets, NB 7-1 derived neurons; thin arrows, RP2; curled brackets, EL neurons; arrowheads, CQ neurons; curved arrows, fpCC. Sections of the confocal images were combined, but for the purpose of clarity presented in two layers: the left images (') are dorsal planes, the right images are ventral planes (''). Eve is red; Hb (A) and Sal (B-E) are green; double stained neurons are yellow. (A) In wild type, hb/eve co-expression is detected in aCC, pCC and RP2 in the most dorsal layer (A'). In the ventral layer (A'') fpCC and the first innermost CQ neuron show hb co-expression. (B) In wild type, co-expression with sal is shown only in aCC, pCC, RP2 (B'), occasionally in fpCC (not shown) and in one of the EL neurons (B''). (C',C'') In the hb mutant embryo, RP2 (arrow) and either aCC and/or pCC are missing in several hemisegments (C', broken square bracket). In addition, the number of NB 7-1-derived neurons is decreased (C'', arrowheads). (D',D'') Ectopic expression of hb using scaGal4 as a driver leads to ectopic neurons in medial position (D'', square brackets) and occasionally to additional Sal-positive neurons in aCC/pCC/fpCC positions (D', thick arrow). (E',E'') Ectopic expression of hb using enGal 4 as a driver gives rise to ectopic neurons in the position of the NB 7-1-derived neurons (large square brackets, E''). One hemisegment shows additional Sal staining in fpCC (thick arrow).
