Figure 5.

TGFB3^C409Y does not disrupt BMP signaling during Xenopus gastrulation. Indicated amounts of synthetic mRNAs for human TGFB3, TGFB3^C409Y and Xenopus Noggin were injected into Xenopus laevis embryos to assay perturbations of BMP signaling during gastrulation. The levels of C-terminal phosphorylated SMAD1 (pSMAD1) were examined by immunoblotting. SMAD1 and actin were used as loading controls. Pictured in the lower panel are intact embryos; the BMPR antagonist Noggin disrupts gastrulation while TGFB3^C409Y does not.