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Fig. 5. Spatial distribution of Xp54nrb mRNA during Xenopus early development. Whole mount in situ hybridization is performed on embryos from stage 3 to stage 21. Photomicrographs of whole-mounts and sec- tions through the corresponding whole mounts for stage 3 (A), stage 6.5 (B), stage 11 (C,D), stage 14 (E,F) and stage 21 (G,H) are shown. (A,B) Xp54nrb transcript is detected at the animal pole of cleaving embryos (animal views). (C) Xp54nrb expression in mid-gastrula is found in the ectoderm and mesoderm with a strong expression in dorsal side (lateral view, dorsal on the left). This pattern is confirmed by section analysis (D) which showed labelled of the ectoderm (ec) and in the involuting meso- derm (mes). (E) At early neural stage, the expression is restricted to the developing nervous system (anterior view, dorsal side is up) with a strong expression underlying the neural plate. (F) Transverse section analysis of the stage 14 shows that Xp54nrb is expressed in the sensorial layer of the neuroectoderm (Nes) and absent in the epithelial layer of the neuroecto- derm (Nep), in the notochord (n) and in the somitic mesoderm (ms). (G) At neurula (stage 21, anterior view, dorsal side is up) Xp54nrb expression is high in the anterior neural territories; optic field (of), mesencephalon (Me) and rhombencephalon (Rh) are labelled. Transverse section analysis (H) in a posterior position shows that only the neural tube (nt) is stained at this level. Abbreviations: bl; blastoporal lip, d; dorsal, Ec; ectoderm, end;endoderm, mes; mesoderm, Me; mesencephalon n; notochord, Nes; sensorial layer of the neuroectoderm, Nep; epithelial layer of the neuroectoderm, of; optic field, nt; neural tube, Rh; rhombencephalon, sm; somitic mesoderm, v; ventral. Scale bars 0.5 mm in (A,B), 0.3 mm in (C,D,E,G,H) and 0.1 mm in (F). Black bars in (E,G) represent the position of the corresponding sections in (F,H) respectively. |
