Fig. 5. Defect of the choroid plexus and increase of Cajal-Retzius cell formation in Hes1;Hes3;Hes5 cKO mice. (A-F) HE staining of the dorsal telencephalic midline. In Hes1;Hes3;Hes5 cKO mice, the dorsal midline cells were not flattened but remained pseudostratified at E11.5 and E12.5 (D,D',E,E', asterisks). Even at E15.5, no choroid plexus was formed in Hes1;Hes3;Hes5 cKO mice (F, asterisk). (G-J) Ttr was expressed in the control at E11.5 and E12.5 (G,I) but not in Hes1;Hes3;Hes5 cKO mice (H,J). (K-N,R-U) Cajal-Retzius cells (reelin⁺,Lhx5⁺) of the mutant piriform cortex were increased in number (L,N,S,U arrows), compared with the control (K,M,R,T) at both E11.5 and E12.5. (O-Q) The number of reelin⁺ cells was quantified by counting DAPI⁺ cells on every five sections from four independent embryos for each genotype. ^*P<0.01, t-test. Scale bars: 100 µm in A,D; 200 µm in B,E,G-N; 250 µm in C,F; 50 µm in R-U.