Fig. 3. Expression of DV patterning genes at embryonic stages 9 (st9),10 (st10) and 11 (st11). Colour code indicates the expression of msh (msh-lacZ and Msh protein), ind transcripts and vnd (vnd-lacZ and Vnd protein) in identified NBs (A,B,E) and the procephalic neuroectoderm (C,D,F). en expression domains are shown for comparison. Orientation of the semi-schematic representations is as in previous figures. (A,C) Stage 9; note the spot-like ind expression in the intercalary (ind is; ind intercalary spot), antennal (ind as; ind antennal spot) and ocular (ind oc; ind ocular spot) head region; the ind antennal spot, in contrast to the intercalary, overlaps completely with the ventral vnd domain; the emerging Dd1 does not express vnd. (B,D) Stage 10; vnd is already downregulated in part of the ventral antennal ectoderm and corresponding Dv3 and Dv6, and is also not expressed in the newly developed Dv5. msh and vnd expression overlaps in a small area of the antennal ectoderm and emerging Dd5. (E,F) Stage 11; note that most of the identified brain NBs (especially protocerebral NBs) do not express any DV patterning gene. (G,I,K) Left half of head flat preparations double labelled for en expression (en-lacZ; Inv protein) and msh (msh-lacZ, Msh protein), ind (transcripts) or vnd (vnd-lacZ and Vnd protein), respectively; broken line marks the ventral midline; insets depict lateral views of stage 11 whole-mount heads. (H,J,L) Close-ups of regions indicated in G,I,K by frames (focus on the level of NBs). Immunopositive NBs are indicated by white, immunonegative NBs by black inscription. (G,H) msh-lacZ/Inv-antibody double labelling. The anterior border of the msh expression domain is positioned immediately posterior to the en hs (G), and runs between the deutocerebral and ocular protocerebral NBs (H). (I,J) DIG ind mRNA/Inv antibody double labelling. (K,L) en-lacZ/Vnd antibody double labelling. Vnd protein has disappeared in most parts of the antennal ectoderm (K) and NBs (L); note the dorsally directed extension of vnd domains in the antennal and ocular procephalic regions. The antennal vnd expression overlaps dorsally with the En-positive Dv8 and Dd5. The posterior border of the ocular vnd domain runs between deuto- and protocerebral NBs (L). AN, IC, MD, MX, antennal, intercalary, mandibular and maxillary segment, respectively; CL, clypeolabrum; FG, foregut; ML, ventral midline; OA, Bolwig organ/optic lobe anlagen; as, en antennal stripe; cl, en expression in the clypeolabrum; hs, en head spot; is, en intercalary stripe; ind is, ind intercalary spot; ind as, ind antennal spot; ind oc, ind ocular spot.