Abstract
This paper reports the cloning and characterisation of a new posterior epidermal marker, X-epilectin, in Xenopus laevis. This gene encodes for a fucolectin, which belongs to the lectin superfamily of carbohydrate binding proteins and specifically binds fucose residues. RT-PCR and in situ hybridisation show that the expression of this gene is switched on during gastrulation and up-regulated during neurula stages and found expressed ubiquitously throughout the epidermis. From tailbud stages, the expression is limited to the dorsal posterior region of the embryo, suggesting that X-epilectin expression is regulated along anteroposterior and dorsoventral gradients during development. In the adult, X-epilectin is mainly expressed in intestinal components, kidney, spinal cord and skin. The effects of growth factors on the regulation of X-epilectin were studied. Change of the fate of animal caps into cement gland or dorsal mesoderm induces a down-regulation of X-epilectin expression in explants treated respectively with ammonium chloride and activin A. We also show that X-epilectin expression is down-regulated by Noggin and tBR and that this effect is inhibited by BMP4 over-expression, suggesting X-epilectin expression is mediated by the BMP signalling pathway.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activins / metabolism
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Amino Acid Sequence
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Ammonium Chloride / pharmacology
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Animals
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Base Sequence
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Bone Morphogenetic Protein 4
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Bone Morphogenetic Protein Receptors
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Bone Morphogenetic Proteins / chemistry*
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Bone Morphogenetic Proteins / metabolism*
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Carrier Proteins
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Cell Differentiation
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Cloning, Molecular
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DNA, Complementary / metabolism
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Down-Regulation
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Gene Expression Regulation
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Gene Expression Regulation, Developmental*
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In Situ Hybridization
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Inhibin-beta Subunits / metabolism
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Lectins / biosynthesis*
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Lectins / chemistry*
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Lectins / metabolism
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Lectins / physiology*
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Models, Genetic
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Molecular Sequence Data
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Proteins / metabolism
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RNA / metabolism
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RNA, Messenger / metabolism
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Receptors, Growth Factor / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Signal Transduction
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Skin / metabolism
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Time Factors
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Tissue Distribution
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Up-Regulation
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Xenopus Proteins / biosynthesis*
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Xenopus Proteins / chemistry
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Xenopus Proteins / physiology*
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Xenopus laevis
Substances
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Bone Morphogenetic Protein 4
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Bone Morphogenetic Proteins
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Carrier Proteins
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DNA, Complementary
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Lectins
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Proteins
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RNA, Messenger
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Receptors, Growth Factor
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X-epilectin, Xenopus
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Xenopus Proteins
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activin A
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bmp4 protein, Xenopus
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fucose-binding lectin
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Ammonium Chloride
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Activins
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noggin protein
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RNA
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Inhibin-beta Subunits
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Bone Morphogenetic Protein Receptors