Figure 4.

CDTa Affects Junctional Components in the Midgut. Reduction in Rab11 Activity Suppresses CDTa Phenotypes in Gut Brush Border and Wings

(A–C) One-week-old tubGAL80ts NP1/+ (control) and tubGAL80ts NP1>CDTa (>CDTa) male flies were incubated at 31°C for 24 h. Guts were dissected and stained with anti-alpha-Catenin (A), anti-Rab11 (B), or anti-Tubulin antibodies (C). Sub-apical (in A) or luminal views (in B, C, and D) taken at 1× (left panels) or 4× magnifications (A and B, right panels; C and D). In (A), thick arrows point at intercellular junctions stained with the anti-alpha-Catenin antibody. The thin arrows point at intestinal stem cells, in which CDTa is not expressed, showing unchanged levels of alpha-Catenin. Scale bar represents 20 μm. In (B), arrows point at increased apical accumulation of Rab11 in CDTa-expressing enterocytes. Scale bar represents 50 μm in left panels and 10 μm in right panels and for (C).

(D) One-week-old tubGAL80ts NP1/+ (control) +/− Rab11^DN and tubGAL80ts NP1>CDTa (>CDTa) +/-Rab11^DN male flies were incubated at 31°C for 24 h. Guts were dissected and stained with fluorescent Phalloidin. Scale bar represents 10 μm.

(E) Transgenic flies expressing CDTa under the control of wing-specific MS1096 GAL4 (combined with tubGAL80ts) were crossed at 25°C with flies carrying UAS-Rab11^DN, Rab11^J2D/+ (heterozygous recessive loss-of-function mutation, Rab11^−/+), UAS-Crag^RNAi, or control wt flies. Mounted wings were photographed and surface area was quantified with Photoshop and analyzed using Prism8 (F = 45.85, df = 4, p < 0.0001). Data are represented as mean ± SD. p-values were obtained from one-way ANOVA tests.

See also Figures S2–S5.