Fig. 1

Fig. 1. Cdx1b is essential for the development of a functional intestine in zebrafish. A: Western blot showing the depletion of Cdx1b protein in two cdx1b mutants cdx1b^zju1/zju1 (cdx1b^zju1) and cdx1b^zju2/zju2 (cdx1b^zju2) compared with WT at 5 dpf. In WT, Cdx1b showed three isoforms (red arrow head). B: Immunostaining of Cdx1b (red) in the intestines of WT and cdx1b^zju1/zju1. Cdx1b is a nuclear localized protein. DAPI stains the nuclei. Scale bar, 10 μm. C: HE staining showing the disorganized gut epithelium in cdx1b^zju1/zju1 compared with WT at 5 dpf. Scale bar, 10 μm. D: TEM images showing the shortened microvilli and loosened cell-cell junction in cdx1b^zju1/zju1 compared with WT at 5 dpf. Red arrow, microvilli; double headed arrow, length of microvilli; arrow head, cell-cell junction. Scale bar, 1 μm or 0.5 μm (bottom two images). E: WISH showing the decreased expression of fabp2 and near absence of alpi.2 in the cdx1b^zju1/zju1 and cdx1b^zju2/zju2 intestine compared with that in WT at 5 dpf. F: Images showing the blockage of intestinal fluid by visualizing the injected phenol-red at the junction between the intestinal bulb (ib) and mid-intestine in cdx1b^zju1/zju1 compared with WT. n.s, non-specific band. io, intestinal obstruction; sb, swim bladder.