Figure 1
Expression of draxin and its receptor DCC (deleted in colorectal cancer) in the postnatal sub-granular zone. (A) Immunohistochemical localization of endogenous draxin at postnatal day (P) 30. A’, Higher magnification of the boxed region in A. Arrowheads indicate draxin immunoreactivity. (B) Cells expressing β-gal detected by X-GAL staining (left) and immunohistochemistry (right) on the dentate gyrus (DG) of P30 mutant mice heterozygous for draxin (draxin+/−). The exon including the translation start site of the draxin gene was replaced with a β-gal expression cassette in either allele. (C–L) Confocal images of the draxin+/− DG double-labeled for β-gal and either granule cell lineage markers or glial cells, including GFAP (C,C’), Tbr2 (D,D’,I,I’,K,K’), NeuroD1 (L,L’), DCX (E,E’,J,J’), Prox1 (F,F’), NeuN (G,G’) and S100β (H,H’), at P30 (C–H), 3 month-old (I,J), and P2 (K,L). The boxed areas in (C–H,K,L) are magnified in (C’-H’,K’,L’), respectively. In (I and J), merged images of the red (β-gal) and green (marker) channels, and the red channel (β-gal) alone, are provided in the left and right panels, respectively. Arrowheads in (I and J) indicate colabeled cells. Some sections were counterstained with DAPI. The β-gal-immunoreactive cells are considered draxin-expressing, and are mainly restricted to Tbr2-expressing late progenitors and DCX/NeuroD1-expressing neuroblasts, regardless of developmental stages. (M) In situ hybridization analysis of DCC on the P30 DG using antisense or sense probes. (N–Q) Double staining of in situ hybridization for DCC and immunochemistry for granule cell lineage markers including GFAP and nestin (N), Tbr2 (O), NeuroD1 (P) and NeuN (Q) at P30. Arrowheads and arrow in (N–Q) indicate cells expressing both of DCC and markers, and marker only, respectively. (R) Schematic showing expression of the marker molecules, draxin and DCC in astrocytes and cells in the granule cell lineage during differentiation. gcl: granule cell layer; h: hilus; ml: molecular layer; FDJ: the fimbriodentate junction; gc: granule cell; pcl: pyramidal cell layer. These abbreviations also apply to the other figures in this paper. Scale bars: (A–J,M) 100 µm; (K,L,N–Q), 20 µm.
