Fig. 3

Expression of ems (a–c), col (e–i) and cnc2 (j, k) singly (a, b, j, k) or in combination with SP5/btd (c–i). All panels show ventral views. a′, b′, j′, k′—nuclear stain of the same embryos a (stage 2.3, early) First expression of ems in a pair of bilateral domains. b (stage 4.2) Late segmental expression of ems. c (stage 2.3, early) ems expression lies anteriorly adjacent to the antennal part of the SP5/btd expression, hence located in the anterior antennal segment. d (stage 2.3, late) Overlap of ems and SP5/btd in the lateral part of the antennal domain (double headed arrow). e (stage 2.2, late), enlarged in f. First col expression (dark shading of nuclear stain by the BM-purple substrate) overlaps with the early expression of SP5/btd but is located a few cell widths more posterior. g (stage 2.3, early) col expression overlaps the posterior of SP5/btd expression, as SP5/btd becomes restricted to the condensing head field. h (stage mid-2.3) The col domain has narrowed down and is posteriorly included in the antennal/intercalary SP5/btd domain. i (stage 2.3, late) The col domain has split into an antennal and an intercalary stripe. j (stage 3.2) First appearance of cnc2 expression in a stomodaeal domain and within the mandibular segment. k (stage 4.2) Late segmental and stomodaeal expression of cnc2. st = developing stomodaeum, md = mandibular segment