(A–C) Examples of dying 16-SGs (dotted outline) in wild-type (A), mnk6006/Df(2L)Exel7077 mutant (B), and p535A-1-4/Df(3R)ED6096 mutant (C) testes. Lysotracker (red), Lamin Dm0 (green), DAPI (blue) and Vasa (white). Bars: 5 µm. (D) SG cyst death by stage in mnk/chk2 and p53 mutants 6 hr after irradiation with 100 rad and 2000 rad (Mean ±SD, p-value *<0.05 t-test). Fixed, stained samples were used for scoring. Testes sample n ≥ 11 for each genotype, repeated in triplicate. (E) Number of Lysotracker-positive SG per 16-SG cyst in mnk/chk2 and p53 mutants following 100 rad. Red line, mean. Unfixed samples stained with Lysotracker, FM 4–64, and Hoechst 33342 were used for scoring.