Fig. 7. 5' upstream regulatory sequences of FoxF1 direct gene expression into the lateral plate mesoderm and are responsive to BMP4 induction. (A) Diagram of a GFP reporter construct used to map the regulatory sequences of FoxF1 in transgenic embryos. (B) A transgenic Xenopus tadpole displaying GFP fluorescence in the ventral half of the body. (C) Same embryo in transmitted light. (D) A cross-section of the tadpole hybridized with digoxigenin labeled anti-GFP probe showing expression of the GFP RNA in the lateral plate mesoderm. (E) A cross-section of the embryo hybridized with digoxigenin labeled anti-GFP probe showing expression of the GFP RNA on one side of the embryo. (F) Diagram of a LacZ reporter construct used to map the regulatory sequences of FoxF1 in transgenic embryos. (G) A transgenic Xenopus embryo displaying LacZ staining in the ventral half of the body. (H) The pBS-FoxF1-NLS-LacZ reporter construct does not show any expression of LacZ in cultured animal caps from injected embryos but shows high levels of expression when co-injected with BMP4 RNA (I).