Fig. 6. CBF1 inhibits BMP signaling. (A) A luciferase reporter assay using a BMP-responsive reporter construct in the presence of CBF1 or CBF1^AA mutant. HEK 293 cells transfected without (-) or with (+) pcDNA/ALK3-CA, Smad1, and Smad4 were measured for luciferase activities in the presence of pcDNA (vector), CBF1/pcDNA (CBF1) or CBF1^AA/pcDNA (CBF1^AA) by cotransfection. The values are represented by fold induction compared with the basal activity of pcDNA (vector). Data are shown as the mean±s.d. of triplicate experiments. (B) Expression of BMP2 and Ventroptin in the E8 chick retina. Section in situ hybridization was performed with antisense probes for BMP2 (a,b) and Ventroptin (c,d). BMP2 was expressed in a double-gradient pattern that is complementary to Ventroptin. (a,c) Horizontal sections. Nasal (anterior) is upwards, temporal (posterior) is downwards. (b,d) Coronal sections. Dorsal is upwards, ventral is downwards. Scale bars: 600 µm. (e) Schematic representation of the expression patterns of BMP2 and Ventroptin in the retina. (C) Horizontal section in situ hybridization of E8 temporal retina transfected with Ventroptin/RCAS (b) or BMP2/RCAS (d). In the temporal region of a control retina, BMP2 was expressed in the GCL and INL (a). When Ventroptin/RCAS was electroporated, expression of BMP2 was completely repressed (b). In the nasal region of a control retina, Ventroptin was expressed in the INL (c). When BMP2/RCAS was electroporated, expression of Ventroptin was completely repressed (d). Scale bar: 100 µm. (D) Horizontal section in situ hybridization of E8 temporal retina transfected with BMP2/RCAS (b) with a probe for ephrin A2. Ephrin A2 was mainly expressed in the GCL in the nasal region (a). When BMP2/RCAS was electroporated in the retina, expression of ephrin A2 was completely repressed (b). (E) Horizontal section in situ hybridization of E8 temporal retina transfected with CBF1/RCAS (b) or CBF1^AA/RCAS (d) with a probe for BMP2. Electroporation of CBF1/RCAS (b) or CBF1^AA/RCAS (c) resulted in repression of BMP2 expression in the GCL in the temporal retina of E8 embryos. The temporal region of untransfected retinae (control) are shown in a,c.

Return to article