Postnatal expression of survivin mRNA in neural precursor cells. Sagittal sections of brains were used to examine expression of survivin. (A, B) At P7, Survivin mRNA was detected in the DG, SVZ, RMS, OB, and EGL of controls (A), and absent in the SVZ and RMS, but not in the DG and EGL of SurvivinCamcremouse brains (B). (C-E) Double labeling to detect survivin mRNA (blue) and NeuN protein (orange) expression in the SVZ-RMS (C, D) and the DG (E) in P7 control brains, shows that survivin is not expressed in NeuN+ cells. D is a magnified view of the dashed box in C. (F-I) Survivin mRNA expression at P35 is restricted to neural precursor cells in the SVZ, RMS and SGZ in control mice (F, H). Survivin expression is reduced in the SVZ and RMS (G), but not in the SGZ (I) of SurvivinCamcremice (ko) as compared to controls (wt). (J-O) Sagittal sections of control P7 brains through the SVZ (J-L) and through the SGZ (M-O) were stained for PCNA (red nuclei) (J, M) and survivin mRNA (white cytoplasm) (K, N) and the confocal images were overlaid (L, O). Only a subpopulation of PCNA+ cells express survivin. EGL, external germinal layer; OB, olfactory bulb; LV, lateral ventricle. Scale bars: A, B 1000 μm; C, F, G 500 μm; D 50 μm; E 200 μm; H, I 100 μm, J-O 20 μm.