Fig. 4: PLXNA1 and PLXNA2 could also contribute to SEMA3F signaling in the human fetal nose.

Since SEMA3F can signal not only through PLXNA3, but through the PLXNA1-A4 family, additional stainings were performed to check for PLXNA1-A4 expression in the nasal compartment of a GW7.5 human fetus (a,b). In addition to PLXNA3, migrating gonadotropin-releasing hormone (GnRH) neurons and the olfactory/vomeronasal scaffold also express PLXNA1 (c,d) while PLXNA2 was detected in GnRH neurons and other cells of the migratory mass, but not in the olfactory/vomeronasal projections (e,f). However, PLXNA4 immunoreactivity was only found in scattered cells, distant from the migratory route of GNRH neurons (g,h). ob olfactory bulbs. Scale bars: (b) = 500 µm; (e,c,g) = 10 µm.