Dvl-2 is expressed in OSN, in all layers through the olfactory bulb and is associated with synapses inside the glomeruli.

<p>Dvl-2 is expressed as early as E13 (A) throughout the OE. During embryonic development some cells showed higher levels of expression than others (B, arrows) and after birth, Dvl-2 expression was restricted to the mature OSN layer of the OE (C, D). Dvl-2 expression was not restricted to the cytoplasm, but was also detected in the nucleus (D, inset). In the developing OB, Dvl-2 was observed as early as E13 (E), and it was detected up to adult (F–H). Even though Dvl-2 was detected in all layers, levels of expression differed between layers and in between animals of the same age (especially after birth). Glomeruli showed a punctate distribution of Dvl-2 (I) similar to that observed for Dvl-1. Dvl-2 expression was not restricted to the cytoplasm and processes, but it also showed nuclear expression, although this expression was not observed in all cells of any given cell type. Electron microscopy images of Dvl-2 stained sections showed that inside the glomerulus, Dvl-2 is in the presynaptic terminal (J). K: In agreement with the immunofluorescence, electron micrographs of periglomerular cells showed some nuclei with Dvl-2 expression (M), while others showed no evidence of Dvl-2 expression (L). Nuclei were counterstained with DRAQ5 (blue). Scale bar = 20 µm in A–D; 50 µm in E–H; 10 µm in I; 200 nm in K; 1 µm in K. EPL: external plexiform layer; GCL: granule cell layer; GL: glomerular layer; MCL: Mitral cell layer; NC: Nasal cavity; OE, olfactory epithelium; OB: Olfactory bulb; ONL: olfactory nerve layer; V: ventricle.