Figure 6. Lack of Usp9x culminates in deficits in neuroblast number and morphology.

(A,B) The dentate gyrus of P28 Usp9x^loxP/Y (A) and Usp9x^−/Y; Emx1-Cre (B) are shown via DAPI labeling. (C,D) Sections were labeled with antibodies against the microtubule-associated protein DCX, a marker specific for neuroblasts (green). (C’) The higher magnification view of the boxed region in (C) shows numerous neuroblast cell bodies above the subgranular zone (SGZ; double arrowheads in C’). These neuroblasts extend extensive processes into the molecular layer (ML, arrows in C’). (D’) In the mutant however, there were fewer of these cells (arrowheads in D’), and they did not extend processes into the ML. (E) There were significantly fewer neuroblasts in the dentate gyrus of Usp9x^−/Y; Emx1-Cre mice in comparison to controls at P28, P42 and P56. (F) qPCR revealed that there were also significantly reduced levels of Dcx mRNA in the hippocampus of mutant mice at P14. ^***p < 0.001, t-test. GCL – granule cell layer. Scale bar in (B) (A–D) −150 μm; C’,D’ −25 μm.