Figure 1.

At E12.5 in a sagittal section (A) SDF-1 mRNA is expressed by mesenchymal cells between the OE and the VNO and between the arrowheads of the OB. B, In an adjacent section to A, CXCR4 is expressed in the OE and the VNO and by cells dispersed in the nasal mesenchyme (arrows) between the VNO and the OB. In A, B, rostral is left, and dorsal is up. C, In a horizontal section SDF-1 expression in the nasal mesenchyme (nm) between the VNO and the forebrain (fb) is evident. D, Many CXCR4-positive cells are present along the pathway of migrating GnRH neurons in the nasal mesenchyme and into the fb (arrows). In C, D, rostral is down, and caudal is up. Scale bar, 100 μm.