Xenbase Image ID: 74592

Figure 3.Induction of cardiogenesis in the VMZ assay is specific to certain Wnt antagonists. (A) The BMP antagonists Noggin and Chordin did not induce specific markers of cardiogenesis (TnIc or MHC-alpha) despite induction of m. actin and elongation of the explants (not shown). Noggin did not induce Tbx5, Nkx2.5, or Nkx2.10, whereas chordin weakly induced these genes. Note that Tbx5 and Nkx2.5 are expressed in tissues other than cardiac mesoderm and that induction of these genes (in the absence of other markers) does not necessarily indicate heart field specification (see text). (B) Wnt antagonists not normally present in gastrula-stage embryos induced weak expression of Tbx5, Nkx2.5, and Nkx2.10 but did not induce the more specific cardiac markers TnIc or MHC-alpha. In situ hybridization for expression of Nkx2.5 (C) and TnIc (C'') indicated that only WIF-1 induced detectable levels of Nkx2.5 expression (arrow in H; 4 of 24 explants showed expression) and that none of these mRNAs induced TnIc. Arrowheads in F and F' show pigmented cement glands that formed in explants injected with chordin mRNA Image published in: Schneider VA and Mercola M (2001) Copyright © 2001. Image reproduced on with permission of the Publisher, Cold Spring Harbor Laboratory Press. This is an Open Access article. Larger Image Printer Friendly View

Return to previous page