FIGURE 3.

Regulation of Wnt signaling by XTNIK in Xenopus embryos. mRNA for Xβ-catenin (Xβ-Cat, 25 pg), n-β-gal (500 pg), XTNIK-WT-Myc (500 pg), or XTNIK-K54R-Myc (500 pg) was injected in the indicated combinations into the ventral marginal zone of eight-cell stage embryos. A, expression of Xβ-catenin, Myc-tagged XTNIK (WT or K54R), and β-actin (loading control) proteins was determined by immunoblotting. B, representative appearance of tadpoles and the ratio of tadpoles with secondary axis formation. Complete indicates axis formation with head-to-trunk structures. Partial indicates axis formation without heads. Secondary axes with or without cement glands were counted as complete or partial, respectively.