Figure 5. WT flies fed B. thailandensis-infected food are killed and have enlarged crop.

(A) Survival of WT flies on infected food at 25°C. Flies kept on infected food died within 3.5 days after they were placed on this food. Second set of flies (trf) was kept on infected food and transferred to normal food, free of bacteria, at 44 hr (black arrowhead). The survival of the tranferred flies was slightly increased in comparison to the non-transferred group, but this difference was not significant. Controls were fed either food containing heat-killed B. thailandensis or no bacterium. The survival of the control groups was not affected. Sample size was at least 40 flies per condition. (B) Dissected gut of WT male D. melanogaster fed food infected with GFP-labelled B. thailandensis. The presence of the bacteria in the crop is confirmed by green fluorescence, which is visible only in the infected flies. (C) An uninfected control had a smaller crop. The crops of the infected and uninfected flies are shown at a higher magnification [magnified crop]. At least 3 flies were imaged per condition. Yellow arrowheads point to crop; white asterisks mark the proventriculus. Scale bars represent 500 µm.