Injected Xwnt-8 RNA acts early in Xenopus embryos to promote formation of a vegetal dorsalizing center

Author: Smith, W.C.; Harland, R.M.

Description: Expression cloning from a pool of gastrula cDNAs identified the Wnt family member Xwnt-8 as having dorsal axis-inducing activity in Xenopus embryos. Microinjected Xwnt-8 mRNA was able to rescue the development of a dorsally complete anterior-posterior axis in embryos ventralized by exposure to UV light. Axis induction was observed in embryos injected in either marginal or vegetal blastomeres at the 32-cell stage. Vegetal blastomeres receiving Xwnt-8 mRNA contributed progeny not to the induced dorsal axis, but to the endoderm, a result consistent with Xwnt-8 causing cells to act as a Nieuwkoop center (the vegetal-inducing component of normal dorsal axis formation), rather than as a Spemann organizer (the induced dorsal marginal zone component that directly forms the dorsal mesoderm). Xwnt-8, which is normally expressed ventrally in midgastrula and neurula embryos, appears to mimic, when injected, maternally encoded dorsal mesoderm-inducing factors that act early in development.

Subject Headings: Animals; Blotting, Northern; Chlorides/pharmacology; Embryonic Induction/drug effects/radiation effects; Gene Expression; Lithium/pharmacology; Lithium Chloride; Microinjections; Morphogenesis/drug effects/radiation effects; Nucleic Acid Hybridization; RNA, Messenger/genetics; Ultraviolet Rays; Xenopus laevis/embryology

Publication year: 1991

Journal or book title: Cell

Volume: 67

Issue: 4

Pages: 753-765

Find the full text :

Find more like this one (cited by):,16&hl=en

Type: Journal Article

Serial number: 2813