Fig. 5.

More cells undergo apoptosis in dmt mutants. A–F: Apoptag (TUNEL [terminal deoxynucleotidyl transferase–mediated deoxyuridinetri-phosphate nick end-labeling]; red) and αTgo (green) staining reveals a general increase in cell death as well as an increase in tracheal-specific cell death at multiple stages in dmt mutants compared with wild-type embryos. G: The number of apoptotic cells in tracheal metamere 4 was counted in each embryo and quantified as percentages of metameres falling into each group: no apoptosis (0), 1–2, 3–4, and 5 or more cells undergoing apoptosis.