Fig. 3. Genetic interactions in the trachea. Stage 15 embryos stained with mAb 2A12 to visualize tracheal tubules and shown with anterior left in sagittal view. (A) Wild-type embryo. (B) Absence of tracheal tubules in homozygous trh¹ mutants. (C) Severe loss of tracheal tubules in jing⁰¹⁰⁹⁴; trh¹ double heterozygotes. (D) Reductions in tracheal branches in jing⁰¹⁰⁹⁴; btl^H823 double heterozygotes. (E) Quantification of jing genetic interactions in the trachea. Double and triple heterozygous combinations (genotype). Data show the percentage of embryos with loss of tracheal branches. Tracheal development in jing⁰¹⁰⁹⁴; trh¹ double heterozygotes is sensitive to the dose of tgo (jing⁰¹⁰⁹⁴; tgo¹ trh¹). jing⁰¹⁰⁹⁴; btl^H823 double heterozygotes show the highest percentage of embryos with tracheal tubule defects. In all cases more than 65 embryos were scored. DB, Dorsal branch; VB, visceral branch; DT, dorsal trunk; TC, transverse connective; LTa, lateral trunk anterior; LTp, lateral trunk posterior.