Fig. 2

Lumen Expansion in bao^s866 Mutants Results from Increased CFTR-Dependent Fluid Secretion

(A) Inhibition of CFTR blocks lumen expansion in bao^s866 mutants.

(Aa) Bright-field images of WT and bao^s866 mutants incubated with DMSO (0.1%) or the CFTR inhibitor T08 (5 μM) from 72 to 120 hpf. Arrows point to the edges of the gut lumen.

(Ab) Confocal images of cross-sections of 144 hpf control and T08-treated bao^s866 mutants. Arrowheads point to delaminating cells. Red is F-actin and blue is DAPI. Scale bars represent 50 μm.

(Ac) Quantification of the gut phenotype in control and T08-treated bao^s866 mutants. Larvae were placed in three phenotypic categories (no phenotype, mild phenotype, or severe phenotype) and then genotyped.

(B) Activation of CFTR in WT phenocopies the gut lumen expansion defect of bao^s866 mutants.

(Ba) Bright-field image of 144 hpf WT larva treated with DMSO (0.15%) or CFTR-Act9 (15 μM). Arrows point to the edges of the gut lumen.

(Bb) Confocal images of cross-sections of 144 hpf control and CFTR-Act9-treated WT larvae. Red is F-actin and blue is DAPI. Scale bars represent 20 μm.

(C) Cftr expression and localization is not affected in bao^s866 mutants compared to WT.

(Ca) Immunoblot of 120 hpf WT and bao^s866 mutants probed against Cftr and β-tubulin.

(Cb) Confocal images of whole mounts of 120 hpf WT (top) and bao^s866 mutant (bottom) stained for Cftr. Arrows point to the apical surface of the gut. Anterior is to the right. Scale bars represent 50 μm.