Fig. 6. Grg1 restricts cells to the neuroepithelial layer. (A) DAPI staining (a), and in situ hybridization for Sox2 (b), Sox14 (c) and ER81 (d) in Grg1-misexpressing E8 tecta visualized using by RCAS-Grg1. (B-D) In situ hybridization for Cash1 in E8 tecta that were transfected with RCAS-AP (B), RCAS-Grg1 (C) or RCAS-Grg4 (D). (E) Immunostaining for Grg4-HA in green and Hu-C/D in red. (F,G) Immunostaining for HA in green and BrdU in red in E8 tecta that were transfected with RCAS-AP (F) or RCAS-Grg4 (G). Cash1 is expressed in the ventricular layer (VL, B). In the Grg1-misexpressing region, Cash1 expression is repressed (C) so that all laminae (IV-I) are incompletely formed on E8 tecta (A). In the Grg4-misexpressing region, expansion of the ventricular layer by postmitotic neuronal precursors is observed (D,E,G). Scale bars: 100 µm for A-E; 50 µm for F,G.