Figure 6

Varicose is required for tracheal development. (A-F) The tracheal lumen of early stage 16 vari mutant embryos were labeled with MAb2A12. In both WT (A) and in embryos heterozygous for the original EP insert and a precise excision of that insert (B), the diameter of the Dorsal Trunk (DT) is uniform, and the Lateral Trunk (LT) is continuous with the DT. All vari mutants (C and heteroallelic F), as well as daughterless-GAL4 mediated RNAi knockdown of vari (E) share similar tracheal defects. Mutants exhibit large dilations along the DT (arrowhead, C) and LT (*, C). Some LT branches appear disconnected from the DT (arrow, C). Lumenal staining is reduced in all vari alleles in comparison to WT and control. Tracheal phenotypes of null vari^48EPembryos are restored upon ubiquitous expression of Vari by daughterlessGAL4 (D). Lateral view: anterior to the left, dorsal is up. WT, wildtype. Calibration: 20 μm, A-F.