Fig 1. Brpf1 expression during forebrain development.

(A) At E14.5, β-galactosidase activity (labeled blue, with nuclei stained red) was detected in the marginal zone (MZ) of the cortical hem, but not in the developing neocortex. In the hippocampus, the signal was detected sparsely in the dentate migration stream (dms, marked by a curved arrow). (B) At E17.5, the expression is very weak in the neocortex and hippocampus. Note the sparse signals detected in the dentate migration stream (dms) marked by a curved arrow. (C-E) After birth, β-galactosidase activity appeared in the neocortex and hippocampus. From P3 onwards, β-galactosidase activity was detected in all the six layers of neocortex and in the cornum amonni (CA) field of the hippocampus. The activity in the dentate gyrus was moderate at P3 but became much stronger at P14 and adult. All images were taken from frozen sections prepared from Brpf1 ^l/+ embryos (A-B) or postnatal brains (C-E); the corresponding wild-type sections showed no β-galactosidase staining [55]. Structures of the developing and adult brains were annotated according to published atlases [87–91]. CA1, cornum amonni 1; CA3, cornum amonni 3; CP, cortical plate; DG, dentate gyrus; DG-g, granular cell layer of dentate gyrus; DG-m, molecular layer of dentate gyrus; HP, hippocampus; I-IV, cortical layers I-VI; IZ, intermediate zone; Rad, radial layer of the hippocampus; SVZ, subventricular zone; VZ, ventricular zone. Scale bars, 100 μm.