Fig. 1

NFIX is expressed by maturing ependymal cells lining the lateral ventricles. a Schematic of a coronal section of a postnatal rodent cerebral cortex, at the level of the corpus callosum (CC). LV = lateral ventricle. b Coronal section of a P15 mouse brain stained with DAPI, showing one of the lateral ventricles. The boxed region depicts the approximate region at which imaging was performed. c-e Higher power view of the lateral ventricle region of a P0 brain, showing the expression of NFIX (red, c) and FOXJ1 (green, d). Whereas FOXJ1 expression is evident in ependymal cells at this age, these cells only expressed low levels of NFIX (arrows in c-e). At P5 and P15, co-expression of NFIX and FOXJ1 is clearly evident within ependymal cells (arrowheads in f-h and i-k). This was confirmed with the use of a second ependymal cell marker, vimentin, at P15, as NFIX-immunopositive nuclei were clearly surrounded by vimentin-positive filaments (arrowheads in l-n). At all of these ages, NFIX-positive cells were also detected within the developing ventricular-subventricular zone region (double arrowheads in c, f, i, l). Scale bar (in b): b 500 μm; c-n 30 μm