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Figure S1.
Distance-Dependent Difference of chordin and noggin Effects, Related to Figure 1
(A-C) Scaling of the embryonic pattern to the body size. (A) Examples of larger (top) and smaller (bottom) embryos at the 4-cell stage.
(B and C) Whole-mount in situ hybridization of larger (top) and smaller (bottom) embryos with mixed probes for otx2 (forebrain), krox20 (hindbrain and part of cephalic neural crest), myoD (somite), and sizzled (ventral).
(D and E) In (D), influences of Wnt-related maternal prepatterning (1) and secondary zygotic events (2) are shown. (E) β-catenin-MO injection suppresses both of them.
(F) Schematic of reconstitution assays using mRNA injected-mediated axis rescue in the MO-injected embryos.
(G) BRE (pXvent-2)-luciferase reporter assays for examining suppression of endogenous BMP signals by injection of chordin or noggin mRNA into the triple knockdown embryo. The titration data showed that chordin and noggin exert similar levels of anti-BMP functions.
(H) Suppression of mutual influences and autoactivation of Chordin and Noggin by MOs.
(I and J) Single-blastomere injection of chordin at a high dose (400 pg) in the β-CN-MO embryo. Even at this high dose, chordin induced a discrete dorsal axis (92.9%, n = 14), instead of causing global hyperdorsalization as noggin did (see the following panels).
(K-N) Single-blastomere injection of noggin (8-cell stage) at different doses in the β-CN-MO embryo (lacZ as a tracer). Whole-mount in situ hybridization with mix probes of sizzled and shh (top) or with the myoD probe (bottom). Even at a low dose (25 pg), noggin injection caused almost radial expansion of myoD (100%, n = 10). At a 100-pg dose, shh expression expanded diffusely to the ventral side (100%, n = 15). (N) Schematic summary of results of (K) through (M). Unlike chordin injection, noggin injection promotes an embryo-wide global dorsalization, instead of inducing a discrete dorsal axis. |
