Fig. 6. Sox4 is downregulated in Foxp1 null hearts. In-situ hybridization for Sox4 (A-E), Foxc1 (H,I) and Foxc2 (J,K) and immunohistochemistry for fibronectin (F,G) was performed on wild-type (A,D,F,H,J) and Foxp1^–/– (B,C,E,G,I,K) E11.5 (A-C) and E14.5 (D-K) embryo sections. Sox4 gene expression is significantly decreased in the outflow tract region of Foxp1^–/– hearts at both E11.5 and E14.5 (A-C), while Foxc1, Foxc2 and fibronectin expression is unchanged. Scale bars: 800 µm in D,E,H-K; 400 µm in A-C,F,G.