Fig. 8. Cryostat transverse sections of stage 40 Xenopus pronephroi stained with tubule-specific antibody 3G8 and counterstained with Hoechst. One-cell stage embryos were injected with 10 ng Xanx-4 MO, 10 ng Xanx-4 MO and 0.5 ng Xanx-4 mRNA, cultured to stage 40 and subjected to whole-mount antibody 3G8 staining. The embryos were acrylamide embedded, cryostat sectioned at 12 µm and lifted on to subbed slides. The slides were counterstained with Hoechst, inspected under light and u.v. illumination. (A) A schematic representation of B showing pronephric tubule sections illustrating true transverse sections, which were scored (filled) and partial longitudinal sections which were not counted (unfilled). (C,D) Normal uninjected control embryo. (E,F) Embryo injected with 10 ng Xanx-4 MO showing enlarged pronephric tubule phenotype. (G,H) embryo injected with 0.5 ng Xanx-4 mRNA and 10 ng Xanx-4 MO showing partial rescue of pronephric tubule phenotype. C,E,G are viewed under UV illumination to identify Hoechst nuclei staining. B,D,F,H are viewed under partial white light and u.v. illumination to identify 3G8 pronephric tubule staining and Hoechst nuclei staining.