Fig. 4: Cep55 deletion results in binucleated cells in the cortex.

a Scheme showing preparation of cells from E16.5 cortices for flow cytometry analysis. b Dot plots showing Ki67 staining and DNA content in Cep55^+/+ and Cep55^−/− cortical cells. Histograms show DNA content of the Ki67-negative (Ki67−) cell populations in the lower boxes. c Quantifications from b. n = 3 and 6 mice per genotype, respectively; n cells > 3000. CTR, control; ^−/−, Cep55^−/−. P-values calculated using Student’s two-tailed unpaired t-test. d, e Confocal optical section of E16.5 cortex from Cep55^−/− brain stained with DAPI (DNA), plasma membrane (PM) stain, and active caspase 3 (C3A). Left boxed areas in d and e are magnified on the right. PM-3D rendering highlights connection of the two cells by a channel. f Top, enlargements of boxed areas from PM and C3A panels in e. Below, corresponding plots showing the fluorescence intensity along the dotted lines, in arbitrary units. Note that the PM appears interrupted. g Left: Immunohistochemistry of P0 Cep55^+/+ and Cep55^−/− cortices for the neuronal marker NeuN. Magenta arrows, NeuN-positive doublets; black arrow, abnormally large nucleus. Right: Quantification of abnormal NeuN-positive (NeuN+) nuclei shown in g. Control includes Cep55^+/+ and Cep55^+/− mice. n = 3 mice per genotype; n = 325 and 284 cells quantified, respectively. P-values calculated using Student’s two-tailed unpaired t-test. h Confocal 3D images of E13.5 cortex from brains of the indicated genotypes stained with DAPI (DNA), Aurora B (green), and MKLP1 (Magenta). Boxed areas are magnified at right. i Quantification of intercellular bridges (ICBs) as shown in boxed areas in h. n = 3 mice per genotype; n = 95 and 59 ICBs, respectively. P-values calculated using Student’s two-tailed unpaired t-test. All bar charts show mean ± SD. Source data for c, g, and i are provided as a Source Data file.