Fig. 7
From: Dynein activating adaptor BICD2 controls radial migration of upper-layer cortical neurons in vivo
Impaired mitotic progression of a subset of ectopically dividing progenitors is related to positioning of the nucleus and centrosomes. a. Coronal cryo-sections of E14.5 cortices from Bicd2fl/fl;Emx1-Cre−/− (=Emx1-WT) and Bicd2fl/fl;Emx1-Cre−/+ (=Emx1-KO) mice. Cortical sections were stained with the DNA marker DAPI (blue), the centrosome marker Pericentrin (magenta) and the mitotic markers Phospho-Vimentin (green) and Phospho-Histone H3 (PH3, red). Arrows showing apical process of dividing cells containing centrosomes away from the ventricular surface. Zooms showing location of centrosomes (Pericentrin) and chromatin condensation (DAPI) in apical and sub-apical mitotic cells. Emx1-WT + Emx1-KO: Zoom 1: condensed subapical dividing cells with centrosomes. Zoom 2: apical mitotic cells with condensed chromatin and with centrosomes. Emx1-KO: Zoom 3: sub-apical mitotic cell with uncondensed chromatin and without centrosomes. Zoom 4: detached apical process containing centrosomes of mitotic cell in EMX-KO Zoom 3. Scale bars are 50 μm for overview, 5 μm for panels 1–3, and 2 μm for panel 4. b. Distribution of mitotic cells with condensed or non-condensed chromatin, and with or without perinuclear centrosomes, as relative position over the cortical longitude from VS to PS (in %). c. Quantification of chromatin condensation and perinuclear centrosomes in apical and sub-apical mitotic cells (in %) (N = 5–6, n = 15–50). d. Relative position of sub-apical mitotic cells with condensed or non-condensed chromatin, over the cortical longitude from VS to PS (in %) (N = 5–6, n = 15–50). e. Number of centrosomes per area in the outer VZ (N = 6–7, n = 10–80). f. Cleavage plane orientation relative to the VS based on Pericentrin and DAPI staining in apical and sub-apical mitotic cells. CP: cortical plate, PS: pial surface, SVZ: subventricular zone, VS: ventricular surface, VZ: ventricular zone. s.-ap: sub-apical. *** p < 0.001, ** p < 0.005, ns = not significant; error bars are ±SEM. Used tests: Kruskal Wallis test with Dunn’s multiple comparisons (d), unpaired t-test (e)