Fig. 2. Transcriptional regulation of early SPCGs in the salivary gland. -Pasilla staining of stage 13-14 wild-type, fkh, CrebA and hkb mutant embryos reveals the morphology of the salivary gland (A). All embryos are ventral views, with anterior towards the left. This arrangement and positioning of wild-type and mutant embryos is also used for B and C. (D) Left panels are CrebA heterozygotes (lacZ expression in posterior regions), middle panels are CrebA homozygotes and the right panels are fkh homozygotes, all at early stages (stage 11), oriented with anterior towards left and showing lateral views. Salivary gland SPCG expression is controlled by fkh (late) and CrebA (B-D; see Figs S1, S2 in the supplementary material). With a small subset of the genes, including sec62 and TRAP, expression can still be detected in fkh mutants (even late stage), albeit at reduced levels (B). The salivary gland expression of all the tested SPCGs in hkb mutants is comparable with that of wild-type salivary glands (B,C; see Figs S1, S2 in the supplementary material). Arrows indicate salivary gland expression in the mutants.