Anterior-posterior guidance of commissural axons by Wnt-frizzled signaling.
Commissural neurons in the mammalian dorsal spinal cord send axons ventrally toward the floor plate, where they cross the midline and turn anteriorly toward the brain; a gradient of chemoattractant(s) inside the spinal cord controls this turning. In rodents, several Wnt proteins stimulate the extension of commissural axons after midline crossing (postcrossing). We found that Wnt4 messenger RNA is expressed in a decreasing anterior-to-posterior gradient in the floor plate, and that a directed source of Wnt4 protein attracted postcrossing commissural axons. Commissural axons in mice lacking the Wnt receptor Frizzled3 displayed anterior-posterior guidance defects after midline crossing. Thus, Wnt-Frizzled signaling guides commissural axons along the anterior-posterior axis of the spinal cord.
Lyuksyutova
Anna I
AI
Department of Neurobiology, Pharmacology and Physiology, University of Chicago, Chicago, IL 60637, USA.
Lu
Chin-Chun
CC
Milanesio
Nancy
N
King
Leslie A
LA
Guo
Nini
N
Wang
Yanshu
Y
Nathans
Jeremy
J
Tessier-Lavigne
Marc
M
Zou
Yimin
Y
D000818:Animals; D001369:Axons / Q000502:physiology* / Q000648:ultrastructure; D001921:Brain / Q000196:embryology / Q000378:metabolism; D019556:COS Cells; D002490:Central Nervous System / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D003463:Cues; D046508:Culture Techniques; D004058:Diffusion; D051157:Frizzled Receptors; D020869:Gene Expression Profiling; D020439:Growth Cones / Q000502:physiology / Q000648:ultrastructure; D017403:In Situ Hybridization; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000502:physiology*; D011506:Proteins / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013116:Spinal Cord / Q000166:cytology* / Q000196:embryology / Q000378:metabolism; D014162:Transfection; D051153:Wnt Proteins; D060528:Wnt4 Protein; D000094742:Secreted Frizzled-Related Proteins
D051157:Frizzled Receptors; D008565:Membrane Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D043562:Receptors, G-Protein-Coupled; D051153:Wnt Proteins; D060528:Wnt4 Protein; C486339:Fzd3 protein, mouse; C491628:Sfrp2 protein, mouse; D000094742:Secreted Frizzled-Related Proteins; C555582:Wnt4 protein, mouse