Abstract
In the sea urchin embryo, the oral-aboral axis is specified after fertilization by mechanisms that are largely unknown. We report that early sea urchin embryos express Nodal and Antivin in the presumptive oral ectoderm and demonstrate that these genes control formation of the oral-aboral axis. Overexpression of nodal converted the whole ectoderm into oral ectoderm and induced ectopic expression of the orally expressed genes goosecoid, brachyury, BMP2/4, and antivin. Conversely, when the function of Nodal was blocked, by injection of an antisense Morpholino oligonucleotide or by injection of antivin mRNA, neither the oral nor the aboral ectoderm were specified. Injection of nodal mRNA into Nodal-deficient embryos induced an oral-aboral axis in a largely non-cell-autonomous manner. These observations suggest that the mechanisms responsible for patterning the oral-aboral axis of the sea urchin embryo may share similarities with mechanisms that pattern the dorsoventral axis of other deuterostomes.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Acebutolol / metabolism
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Amphibians
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Animals
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Body Patterning / genetics
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Body Patterning / physiology*
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Bone Morphogenetic Proteins / genetics
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Bone Morphogenetic Proteins / physiology*
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Cell Differentiation
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Chlorides / toxicity
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Ectoderm / cytology
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Ectoderm / physiology
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Embryo, Nonmammalian / drug effects
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Embryo, Nonmammalian / physiology*
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Embryonic Induction
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Endoderm / cytology
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Endoderm / physiology
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Gene Expression Regulation, Developmental
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Goosecoid Protein
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Homeodomain Proteins / genetics
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In Situ Hybridization
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Left-Right Determination Factors
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Lithium / pharmacology
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Mice
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Microinjections
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Models, Biological
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Molecular Sequence Data
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Morphogenesis
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Nickel / toxicity
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Nodal Protein
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Oligoribonucleotides, Antisense / metabolism
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Phenotype
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Repressor Proteins*
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Reverse Transcriptase Polymerase Chain Reaction / methods
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Sea Urchins
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Sequence Alignment
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Signal Transduction / genetics
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Signal Transduction / physiology*
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Transcription Factors*
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Transforming Growth Factor beta / genetics
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Transforming Growth Factor beta / metabolism
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Transforming Growth Factor beta / physiology*
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Zebrafish
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Zebrafish Proteins*
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Zinc Compounds / toxicity
Substances
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BMP2-4 protein, Tripneustes gratilla
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Bone Morphogenetic Proteins
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Chlorides
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Goosecoid Protein
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Homeodomain Proteins
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Left-Right Determination Factors
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Nodal Protein
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Nodal protein, mouse
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Oligoribonucleotides, Antisense
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Repressor Proteins
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Transcription Factors
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Transforming Growth Factor beta
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Zebrafish Proteins
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Zinc Compounds
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lft1 protein, zebrafish
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Acebutolol
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nickel chloride
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Nickel
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zinc chloride
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Lithium
Associated data
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GENBANK/AY442295
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GENBANK/AY442296