Expression of HGF/SF, c-met, and tPA in the developing E14 olfactory system. The left panels are bright-field images, and the right panels are corresponding dark-field images. Hybridization of³⁵S-labeled antisense cRNA probes with E14 sagittal sections. A, Expression of HGF/SF is high in the OM of the OC. Lower expression is also observed in the ventricular zone at the anterior end of the LV, which will develop into the olfactory bulb.B, Expression of c-met is observed in the olfactory neuroepithelium lining the OC. C, High-level expression of tPA is observed throughout the olfactory neuroepithelium. Use of ³⁵S-labeled sense HGF/SF, c-met, and tPA (D–F, respectively) cRNA probes detects no specific hybridization. Scale bar, 310 μm.AON, Anterior olfactory nucleus; DON, dorsal anterior olfactory nucleus; EPL, external plexiform layer; GL, also g (Fig. 9), glomerular layer; GCL, granule cell layer;IPL, internal plexiform layer; LON, lateral anterior olfactory nucleus; LV, lateral ventricle; M, meninges; MCL, alsoML (Fig. 3), mitral cell layer; MZ, marginal zone; OC, olfactory canal; OM, olfactory mucosa; ON, olfactory neuroepithelium;ONL, olfactory nerve fiber layer; OV, olfactory ventricle; RMS, rostral migratory stream;SVZ, subventricular zone.