title: Olfactory sensory axons expressing a dominant-negative semaphorin receptor enter the CNS early and overshoot their target.
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.
authors.affiliation: Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Renzi
authors.forename: T L
authors.initials: TL
authors.lastname: Wexler
authors.forename: J A
authors.initials: JA
authors.lastname: Raper
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology; D002642:Chick Embryo; D018274:Electroporation; D005799:Genes, Dominant; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism*; D039942:Neuropilin-1; D009832:Olfactory Nerve / Q000196:embryology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D040121:Semaphorin-3A; D013687:Telencephalon / Q000196:embryology; D014162:Transfection
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D040121:Semaphorin-3A; C095114:collapsin response mediator protein-2; D039942:Neuropilin-1