Abstract
Using combinations of amphibian embryo tissues, it is shown that the selection of genes expressed by a cell is determined by its distance from a source of activin, a peptide growth factor contained in vegetal cells and able to induce other cells to form mesoderm. This long-range signal spreads over at least 10 cell diameters in a few hours. It does so by passive diffusion, because it can by-pass cells that do not themselves respond to the signal nor synthesize protein. These results provide direct support for the operation of a morphogen concentration gradient in vertebrate development.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activins
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Animals
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Cell Division
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Cell Movement
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Culture Techniques
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DNA-Binding Proteins / genetics
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Diffusion
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Embryo, Nonmammalian / physiology
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Embryonic Development
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Embryonic Induction*
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Fetal Proteins / genetics
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Gene Expression Regulation, Developmental
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Goosecoid Protein
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Homeodomain Proteins*
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Inhibins / genetics
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Inhibins / metabolism*
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RNA, Messenger / metabolism
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Repressor Proteins*
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Signal Transduction*
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T-Box Domain Proteins*
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Transcription Factors*
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Xenopus
Substances
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DNA-Binding Proteins
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Fetal Proteins
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Goosecoid Protein
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Homeodomain Proteins
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RNA, Messenger
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Repressor Proteins
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T-Box Domain Proteins
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Transcription Factors
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Activins
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Inhibins
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Brachyury protein