Figure 2.

SMO is required for production of olfactory bulb interneurons in V-SVZ: Ad-GFAPp-Cre virus was injected in either dorsal (A–F) or ventral (G–L) V-SVZ in CAG or Smo^flx/flx; CAG animals, and brain tissue was analyzed 30 days after injection. Approximate locations of the imaged areas are indicated by red boxes. GFP/GFAP double-labeled cells were found at the injection site (arrows in A,D,G,J), and GFP-labeled progeny were scored in the olfactory bulb for all sites and genotypes (C,F,I,L). Scale bars—50 microns; red dashed lines indicate the core of the olfactory bulb. Loss of Smoothened resulted in significant decreases in labeled cells in both the granule cell layer (M) and periglomerular cell layer (N) of the olfactory bulb, regardless of whether virus was injected dorsally or ventrally. Bar plots each show mean value +/− SEM (n = 4 to 5 sections each from each of 4 or 5 animals per location and genotype; p values for unpaired t-test are shown below each plot). This difference was not seen in control dorsal injections of Ad:CMVp-GFP (O) (n = 4 to 5 sections each from each of 3 or 4 animals per genotype). (P) Quantification of BrdU/GFP double-positive cells at the site of injection showed a decrease in BrdU incorporation in labeled cells of the ventral V-SVZ (n = 3 to 4 sections each from each of 3 or 4 animals per genotype; p value for unpaired t-test is shown beneath plot).