Reelin is expressed in the accessory olfactory system, but is not a guidance cue for vomeronasal axons.

Reelin is an extracellular matrix protein that regulates neuronal migration in the developing cerebral cortex, and axon outgrowth in the hippocampus. In the developing vomeronasal system, Reelin mRNA is expressed in perineural cells near the vomeronasal nerve, as well as in the vomeronasal organ, olfactory epithelium and olfactory and accessory olfactory bulbs, suggesting that it might regulate axon guidance or fasiculation. We tested that hypothesis by crossing reeler mice with VN12-IRES-tau-lacZ mice to investigate the role of reelin. The vomeronasal nerves are indistinguishable in normal and reeler mutant mice, strongly suggesting that Reelin does not provide a guidance cue for vomeronasal axons.