Abstract
Sensory axons extend from the chick olfactory epithelium to the telencephalon well before the maturation of their target, the olfactory bulb. During a waiting period of several days, olfactory axons arrive and accumulate outside the CNS while the bulb differentiates beneath them. Semephorin-3A is expressed in the tel-encephalon during this period and has been proposed to prevent their entry into the CNS. We show that the misexpression of a dominant-negative neuropilin-1 that blocks SEMA-3A-mediated signaling in olfactory sensory axons induces many of them to enter the tel-encephalon prematurely and to overshoot the olfactory bulb. These results suggest that chemorepellents can prevent the premature innervation of immature targets.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Axons / metabolism*
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Axons / ultrastructure
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Central Nervous System / cytology
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Central Nervous System / embryology
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Chick Embryo
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Electroporation
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Genes, Dominant
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Intercellular Signaling Peptides and Proteins
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Nerve Tissue Proteins / biosynthesis*
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Neurons, Afferent / cytology
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Neurons, Afferent / metabolism*
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Neuropilin-1
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Olfactory Nerve / embryology*
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Olfactory Nerve / metabolism
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Recombinant Proteins / biosynthesis
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Recombinant Proteins / genetics
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Semaphorin-3A
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Telencephalon / embryology
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Transfection
Substances
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Intercellular Signaling Peptides and Proteins
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Nerve Tissue Proteins
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Recombinant Proteins
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Semaphorin-3A
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collapsin response mediator protein-2
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Neuropilin-1