Cell
Volume 74, Issue 3, 13 August 1993, Pages 433-441
Journal home page for Cell

Article
Processed Vg1 protein is an axial mesoderm inducer in xenopus

https://doi.org/10.1016/0092-8674(93)80045-GGet rights and content

Summary

Vg1 is a TGFβ-related growth factor encoded by a maternal mRNA localized to vegetal blastomeres in Xenopus embryos. Vg1 precursor protein is abundant in vegetal cells, but the processed mature form has not been readily detected and no activity has been demonstrated for the putative Vg1 mature protein. We have engineered a BMP2-Vg1 fusion (BVg1) that promotes formation of mature Vg1 protein in vivo. Injection of BVg1 mRNA induces dorsal mesoderm in animal cap cells, and BVg1 expression in ultraviolet-ventralized embryos fully restores a normal dorsal axis. Blastomeres expressing BVg1 act as a Nieuwkoop center, the region that induces the Spemann organizer. Our results lead us to suggest that localized posttranslational processing of Vg1 precursor protein on the future dorsal side of the embryo is a key step in generating dorsal mesoderm and the body axis in Xenopus.

References (61)

  • NewH.V. et al.

    Inductive interactions in early embryonic development

    Curr. Opin. Genet. Dev.

    (1991)
  • NishimatsuS. et al.

    Genes for bone morphogenetic proteins are differentially transcribed in early amphibian embryos

    Biochem. Biophys. Res. Commun.

    (1992)
  • RebagliatiM.R. et al.

    Identification and cloning of localized maternal RNAs from Xenopus eggs

    Cell

    (1985)
  • ShimellM.J. et al.

    The Drosophila dorsal—ventral patterning gene tolloid is related to human bone morphogenetic protein 1

    Cell

    (1991)
  • SmithJ.C. et al.

    Expression of a Xenopus homolog of brachyury (T) is an immediate-early response to mesoderm induction

    Cell

    (1991)
  • SmithW.C. et al.

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

    Cell

    (1991)
  • SmithW.C. et al.

    Expression cloning of noggin, a new dorsalizing factor localized to the Spemann organizer in Xenopus embryos

    Cell

    (1992)
  • SokolS. et al.

    Injected Wnt RNA induces a complete body axis in Xenopus embryos

    Cell

    (1991)
  • SteinD. et al.

    Multiple extracellular activities in Drosophila egg perivitelline fluid are required for the establishment of embryonic dorsal—ventral polarity

    Cell

    (1992)
  • ThomsenG. et al.

    Activins are expressed early in Xenopus embryogenesis and can induce axial mesoderm and anterior structures

    Cell

    (1990)
  • VincentJ.P. et al.

    Kinematics of grey crescent formation in Xenopus eggs: the displacement of subcortical cytoplasm relative to the egg surface

    Dev. Biol.

    (1986)
  • VizeP. et al.

    Assays for gene function in developing Xenopus embryos

    Meth. Cell Biol.

    (1991)
  • WeeksD.L. et al.

    A maternal mRNA localized to the vegetal hemisphere in Xenopus eggs codes for a growth factor related to TGF-β

    Cell

    (1987)
  • YounB.W. et al.

    Axial structure development in ultraviolet-irradiated (notochord-defective) amphibian embryos

    Dev. Biol.

    (1981)
  • AsashimaM. et al.

    Mesodermal induction in early amphibian embryos by activin A (erythroid differentiation factor)

    Roux's Arch. Dev. Biol.

    (1990)
  • AsashimaM. et al.

    Presence of activin (erythroid differentiation factor) in unfertilized eggs and blastulae of Xenopus laevis

  • BolceM.E. et al.

    Ventral ectoderm of Xenopus forms neural tissue, including hindbrain, in response to activin

    Development

    (1992)
  • ChasanR. et al.

    Activation of the easter zymogen is regulated by five other genes to define dorsal—ventral polarity in the Drosophila embryo

    Development

    (1992)
  • ChristianJ.L. et al.

    Xwnt-8 modifies the character of mesoderm induced by bFGF in isolated Xenopus ectoderm

    EMBO J.

    (1992)
  • DaleL. et al.

    Developmental expression of the protein product of Vg1, a localized maternal mRNA in the frog Xenopus laevis

    EMBO J.

    (1989)
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      Generally, the late pathway is used to localize RNAs, such as vg1 and vegT, which are necessary for germ-layer patterning in the embryo (Birsoy, Kofron, Schaible, Wylie, & Heasman, 2006; Joseph & Melton, 1998; Kofron et al., 1999; White & Heasman, 2008; Zhang et al., 1998). Importantly, spatially inappropriate expression of either vg1 and vegT mRNAs, which encode, respectively, a TGFβ growth factor family member and a T-box transcription factor, cause lethal embryonic phenotypes (Thomsen & Melton, 1993; Wallace & Dumont, 1968; Zhang & King, 1996). In stage I oocytes, while early localizing RNAs are enriched within the Balbiani body, late localizing RNAs are distributed ubiquitously in the cytoplasm, indicating a clear mechanistic distinction between the two pathways.

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    Present address: Department of Biochemistry and Cell Biology, State University of New York at Stony Brook, Stony Brook, New York 11794-5215.

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