title: Chordin is required for the Spemann organizer transplantation phenomenon in Xenopus embryos.
abstract: We analyzed the Chordin requirement in Xenopus development. Targeting of both chordin Xenopus laevis pseudoalleles with morpholino antisense oligomers (Chd-MO) markedly decreased Chordin production. Embryos developed with moderately reduced dorsoanterior structures and expanded ventroposterior tissues, phenocopying the zebrafish chordino mutant. A strong requirement for Chordin in dorsal development was revealed by experimental manipulations. First, dorsalization by lithium chloride treatment was completely blocked by Chd-MO. Second, Chd-MO inhibited elongation and muscle differentiation in Activin-treated animal caps. Third, Chd-MO completely blocked the induction of the central nervous system (CNS), somites, and notochord by organizer tissue transplanted to the ventral side of host embryos. Unexpectedly, transplantations into the dorsal side revealed a cell-autonomous requirement of Chordin for neural plate differentiation.
authors.affiliation: Howard Hughes Medical Institute and Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Oelgeschläger
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kuroda
authors.forename: Bruno
authors.initials: B
authors.lastname: Reversade
authors.forename: E M
authors.initials: EM
authors.lastname: De Robertis
mesh_terms: D028341:Activins / Q000494:pharmacology; D000818:Animals; D002454:Cell Differentiation; D002490:Central Nervous System / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004627:Embryonic Induction; D005775:Gastrula / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000037:antagonists & inhibitors / Q000502:physiology*; D007124:Immunoenzyme Techniques; D036341:Intercellular Signaling Peptides and Proteins; D008094:Lithium / Q000494:pharmacology; D008648:Mesoderm / Q000378:metabolism*; D009024:Morphogenesis / Q000235:genetics; D009025:Morpholines / Q000737:chemistry; D009672:Notochord / Q000033:anatomy & histology / Q000502:physiology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D016377:Organ Transplantation; D020897:Organizers, Embryonic / Q000502:physiology*; D010641:Phenotype; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D009025:Morpholines; D016376:Oligonucleotides, Antisense; D028341:Activins; C054234:chordin; D008094:Lithium