RRC ID 397
Author Miyasaka N, Sato Y, Yeo SY, Hutson LD, Chien CB, Okamoto H, Yoshihara Y.
Title Robo2 is required for establishment of a precise glomerular map in the zebrafish olfactory system.
Journal Development
Abstract Olfactory sensory neurons (OSNs) expressing a given odorant receptor project their axons to specific glomeruli, creating a topographic odor map in the olfactory bulb (OB). The mechanisms underlying axonal pathfinding of OSNs to their precise targets are not fully understood. Here, we demonstrate that Robo2/Slit signaling functions to guide nascent olfactory axons to the OB primordium in zebrafish. robo2 is transiently expressed in the olfactory placode during the initial phase of olfactory axon pathfinding. In the robo2 mutant, astray (ast), early growing olfactory axons misroute ventromedially or posteriorly, and often penetrate into the diencephalon without reaching the OB primordium. Four zebrafish Slit homologs are expressed in regions adjacent to the olfactory axon trajectory, consistent with their role as repulsive ligands for Robo2. Masking of endogenous Slit gradients by ubiquitous misexpression of Slit2 in transgenic fish causes posterior pathfinding errors that resemble the ast phenotype. We also found that the spatial arrangement of glomeruli in OB is perturbed in ast adults, suggesting an essential role for the initial olfactory axon scaffold in determining a topographic glomerular map. These data provide functional evidence for Robo2/Slit signaling in the establishment of olfactory neural circuitry in zebrafish.
Volume 132(6)
Pages 1283-93
Published 2005-3
DOI 10.1242/dev.01698
PII dev.01698
PMID 15716341
MeSH Animals Axons / metabolism Gene Expression Profiling Glycoproteins / genetics Glycoproteins / metabolism Mutation Nerve Tissue Proteins / genetics Nerve Tissue Proteins / metabolism Olfactory Pathways / embryology* Olfactory Pathways / metabolism Receptors, Immunologic / metabolism* Zebrafish / embryology* Zebrafish / metabolism Zebrafish Proteins
IF 5.413
Times Cited 43
Zebrafish rw031 rw032