Analysis of the possible mechanisms by which Fstl1 regulates the development of radial glial processes. (A) Western blotting for phospho-Smad1/5/8, AKT and phospho-AKT (S473). Similar phosphorylation levels of Smad1/5/8 and AKT in the Fstl1 −/− and WT brains at E14.5. The expression of AKT in the Fstl1 −/− cortices did not differ from that in the WT cortices. (B to C) Quantification of the mRNA levels of BMP7 (B) and AKT1 (C) at E14.5 showed no differences. (D and D’) Etv5 mRNA was predominantly expressed at E14.5 in the VZ of the Fstl1 −/− mice (D’), similar to the expression in the WT mice (D). (E and F) The transcription levels of Etv5 (D) and reelin (F) mRNA did not differ between the WT and Fstl1 −/− mice. (F) (G and G’) The distribution of reelin+ CR cells in the Fstl1 −/− mice also did not differ from that in the WT mice. (H to L) Quantification of the mRNA levels of Cdc42 (H), GSK3β (I) and integrinβ1/α5/α6 (J to L) by RT-PCR showed similar mRNA levels in the WT and Fstl1 −/− mice. Scale bars: 50 μm for D and D’; 100 μm for F and F’. (PDF 723 kb)