Robo2 is required for establishment of a precise glomerular map in the zebrafish olfactory system
Citations Over TimeTop 12% of 2005 papers
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.
Related Papers
- → The Mouse SLIT Family: Secreted Ligands for ROBO Expressed in Patterns That Suggest a Role in Morphogenesis and Axon Guidance(1999)293 cited
- → PlexinA1 is a new Slit receptor and mediates axon guidance function of Slit C-terminal fragments(2014)109 cited
- → Short-Range and Long-Range Guidance by Slit and Its Robo Receptors(2000)236 cited
- → The Expression Pattern of EVA1C, a Novel Slit Receptor, Is Consistent with an Axon Guidance Role in the Mouse Nervous System(2013)20 cited
- → Regulation of Axon Guidance by Slit and Netrin Signaling in the Drosophila Ventral Nerve Cord(2007)21 cited