Figure 4. FoxA is required for pharynx regeneration.
(A) FoxA(RNAi) animals develop dorsal lesions (arrow). (B and C) Confocal images of cryosections stained with antibodies recognizing muscle (α-Tmus), epithelial cells and protonephridia (α-acetylated tubulin), and nuclei (DAPI). Control (B) and FoxA(RNAi) animals (C) are shown 3 days after pharynx removal. Dashed green lines highlight the regenerating pharynx. (D) Tail fragments amputated at dashed red line regenerate brain tissue (Smed-PC2, red arrowheads) but not a pharynx (Smed-PKD2, green arrowheads). (E) Head fragments regenerate posterior intestinal branches (Smed-porcupine, red arrowheads) despite the absence of a pharynx (Smed-PKD2, green arrowhead). (F) Whole-mount ISH for Wnt11-5 in control and FoxA(RNAi) tail fragments 7 days after amputation. Green boxes highlight insets shown below. (G) Ratio of Wnt11-5 expression to total length of tail fragment. Significance determined by Student’s t test. Error bars = SEM. N = 14 fragments. Scale bars, (A), 500 μm, (B and C), 50 μm, (D–F), 200 μm.