title: Depletion of three BMP antagonists from Spemann's organizer leads to a catastrophic loss of dorsal structures.
abstract: Transplanted Spemann's organizer induces dorsal embryonic cell fates such as the nervous system and somites, but in normal development, elimination of individual organizer signals (such as the bone morphogenetic protein [BMP] antagonists) has surprisingly modest effects on these tissues. Thus, the role of BMP antagonists may be limited to fine tuning the size of the dorsal domain. However, at least five BMP antagonists are specifically expressed in the organizer, and all can mimic aspects of organizer function, suggesting overlapping functions. Here, we deplete the function of three BMP antagonists, chordin, noggin, and follistatin, in Xenopus tropicalis. We demonstrate that this results in catastrophic failure of dorsal development and expansion of ventral and posterior fates. We conclude that BMP antagonists are required for formation of the neural plate and dorsal mesoderm. In addition, our results show that neural specification requires the continuous activity of BMP antagonists from blastula through gastrula stages.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, 142 LSA, Berkeley, California 94720, USA.
authors.forename: Mustafa K
authors.initials: MK
authors.lastname: Khokha
authors.forename: Joanna
authors.initials: J
authors.lastname: Yeh
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Grammer
authors.forename: Richard M
authors.initials: RM
authors.lastname: Harland
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors*; D002352:Carrier Proteins; D005260:Female; D038681:Follistatin / Q000235:genetics / Q000378:metabolism; D005775:Gastrula / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism*; D020897:Organizers, Embryonic / Q000166:cytology / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D014981:Xenopus / Q000196:embryology / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D000099176:Noggin Protein
chemical_list: D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D038681:Follistatin; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D000099176:Noggin Protein; C100866:cer1 protein, Xenopus; C094620:nodal3.1 protein, Xenopus; C054234:chordin