Fig. 7. Roles of VM-bnl in tracheal development. vN and tN (N is an arbitrary integer) indicate VM-PS and Tr number, respectively. (A-C) Wild type. (D,E) bap-GAL4/+; UAS-bnl/+. (F,G) wg^ts embryo shifted up during early midstage 11 (5.36.3AEL). (H) twi-GAL4/+; UAS-dTCF-N/+. Late stage 11 to early stage 12 embryos are stained with FAS2, TIN or FAS3 as indicated. Lateral views are shown except for (B1, F1, H1), which are ventral views. Vertical bars, VM-PS borders. Panel interpretation is shown below. The region labeled with a bracket in A is enlarged in B2. (A-C) Relationship between VB budding and VM-bnl expression in wild type. (A) VB buds towards VM-bnl domains in a 1:1 fashion at late stage 11. (B) VB of Tr8 first touches the posterior vicinity of the TIN-expressing a region of VM-PS11. (C) At early stage 12, several cells touch with the p and a region expressing tin/bnl. (D,E) Misexpression of bnl in the entire VM caused misrouting (D) or bifurcation (E) of VB (arrows). (F-H) Reduction of tin/bnl expression domain using wg^ts mutant (F,G) or UAS-dTCF-N (H) causes misrouting of VB towards the p region of VM-PS10 (F2) or VM-PS10-11 border (H2), respectively. (I) VB shift in wg or WG signaling mutants is schematically shown.