Fig. 3

Severe loss of cortical tissue in Akirin2 knockout embryos. a Hematoxylin and eosin staining of coronal sections of control and Akirin2 knockout cortex (ctx) at E12, shown at two locations on the rostro-caudal axis. The knockout contains only a thin epithelium dorsomedially and exhibits cells falling/spilling into the lateral ventricle (LV). b Closeup images of boxed areas in (a); arrows show cells spilling into the LV. c, d Comparative low (c) and higher (d) magnification images of tdTomato reporter and Sytox Green fluorescence in coronal sections of control and Akirin2 knockout cortex at 4 locations on the rostro-caudal axis. In the knockout, there are still tdTomato cells present, although these are drastically fewer in number and found only laterally, or situated in a thin epithelium dorsally. e Control and knockout sagittal sections at E11 showing tdTomato-positive cells. In the knockout at this timepoint, cells are already observed spilling in the LV (arrows) and cell loss is more pronounced rostrally than caudally. f Higher magnification of boxed area in (e); arrows show individual cells that are double positive for tdTomato and Sytox Green within the LV. di, diencephalon; LGE, lateral ganglionic eminence; MGE, medial ganglionic eminence; SA, septal area. Scale bar: 200 μm in (b, c, d, e); 90 μm in (f)