Fig. 2.

Robust and rapid apoptosis following Knl1 deletion. a Cleaved Caspase 3 (CC3) immunostaining showed extensive apoptosis in E15.5 cKO cortex (scale bar: 100 µm). b DAPI staining revealed an abundance of pyknotic nuclei in E15.5 cKO cortex (scale bar: 50 µm). Many pyknotic nuclei exhibited a stereotyped clustering (arrowheads). c CC3 immunostaining showed that apoptosis was present in E13.5 cKO cortex, one day after the onset of hGFAP-Cre-mediated Knl1 deletion at E12.5. d At E15.5, near the peak of neurogenesis, CC3 staining (green) was extensive in cortical VZ, SVZ, and intermediate zone (IZ), but largely absent from RBFOX3+ (NeuN+) cortical plate (CP) neurons (red) in cKO. e By E17.5, CC3 staining showed only a moderate increase in cKO compared to ctrl (scale bar: 50 µm). f, g Analysis of E16.5 cortex following a 4-h pulse of CldU (red) and a 24-h pulse of EdU (blue, scale bar: 100 µm). CC3 staining (green) showed no apoptosis in CldU+ cells (open arrowheads) in ctrl or cKO, but revealed extensive apoptosis in EdU+ cells (solid arrowheads) in cKO. EdU+ migrating neurons (yellow arrows) were present in the IZ of ctrl but largely absent from cKO (inset scale bar: 20 µm). h Quantification of CC3 colocalization with CldU or EdU (mean, two-tailed unpaired t-test, n = 3 animals). LGE lateral ganglionic eminence, h hours