Omp mRNA localizes to axons of OSNs but not VSNs. (a) OSN axons in the main olfactory bulb (MOB) contain FXGs (green, indicated by FXR2P immunostaining, arrows), Omp mRNA (red, indicated by Omp in situ hybridization, arrows), and OMP protein (blue, indicated by OMP immunostaining). (b) VSN axons in the accessory olfactory bulb (AOB) do not contain FXGs or Omp mRNA, but do contain OMP protein. Scale bar: 5 μm