Fig. 3: Cell death in D. melanogaster is triggered by the consumption of cosmomycin D producing spores.

a Third instar larvae that have fed on media containing spores of WAC-288. After feeding, larvae were dissected and processed for fluorescence microscopy for the detection of activated Dronc which is the caspase-9 homolog in Drosophila (Scale bar = 1 mm) Specific regions of the (b) anterior and (c) posterior/hindgut were identified and visualized (Scale bars = 1 mm). Images at a higher magnification of the (d) anterior midgut shows lower levels of Dronc activation compared to the (e) posterior midgut which displays higher levels of activation (Scale bars = 50 µm). f Activation of Dronc in posterior midgut of larvae that fed on food containing 1 mg of pure cosmomycin D isolated from WAC-288 (Scale bar = 1 mm). g No activation in the posterior midgut of larvae that were fed spores of the cosmomycin D deficient mutant ∆cosD-orf1222 (Scale bar = 1 mm). h Spores of S. avermitilis are visible and accumulate in the posterior midgut and hindgut (Scale bar = 1 mm). i Lack of Dronc activation within the indicated regions of larval guts that were fed S. avermitilis. Each result was individually reproduced three times with similar results (Scale bar = 1 mm).