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Figure 1. Whole-mount in situ hybridization analysis of XPtf1a/p48 expression during Xenopus embryogenesis and in comparison to XlHbox8. (A) Dorsal view of a stage 20 embryo, anterior toward the left. XPtf1a/p48 transcripts (blue) are detected along two parallel longitudinal stripes representing the neural folds. (B) Double-staining in situ hybridization of tailbud-stage (stage 26) embryos using En2 (red) as a midbrain–hindbrain boundary marker (white arrowhead) and Krox20 (red) as a marker for rhombomeres 3 and 5 (black arrowheads). Neural expression of XPtf1a/p48 becomes restricted to the hindbrain, with the anterior end defined by the midbrain–hindbrain boundary and the posterior limit by rhombomere 5. XPtf1a/p48 transcripts are also becoming detectable in the developing retina. During later phases of development, retinal expression is confined to the proliferating precursor cells of the ciliary marginal zone and expression in the neural tube to dorsal elements (shown in E,F). (C,D) Lateral view of stage 28 and stage 35 embryos stained for XPtf1a/p48 expression. (E–G) Transverse sections (S1, S2, S3) of a stage 35 embryo at the levels indicated in D, dorsal to the top. (H) Lateral view. (I) Ventral view. (J,K) Lateral and ventral view of XlHbox8 expression. (duo) Duodenum; (dp) dorsal pancreatic bud; (st) stomach; (vp) ventral pancreatic buds. |
