Fig. 1. Expression of Gdf11 in the neural tube causes rostral displacement of Hox expression domains. (A-H) Hoxc6-Hoxc10 expression in longitudinally sectioned (A-D), and in cross-sectioned (E-H) spinal cords taken from HH stage 25 embryos 3 days after Gdf11 electroporation. The electroporated side (on the right in all panels) is marked by GFP expression. White arrows indicate the caudal expression limit of Hoxc6 (A) and the rostral expression limits of Hoxc9 (C) and Hoxc10 (D) in the control side. Yellow arrows indicate the caudal expression limits of Hoxc6 (A) and Hoxc8 (B) in the electroporated side. (A,C) The same section double labeled with Hoxc6 and Hoxc9. Broken lines in A-D indicate the RC levels of sections (E-H). (E,G) The same section double labeled with Hoxc6 and Hoxc9; (F,H) the same section double labeled with Hoxc8 and Hoxc10. (I) A diagram depicts the normal Hox expression domains in the control (CTL) side and the rostral displacement of Hox expression domains in the Gdf11 electroporated side (EXP) of the spinal cord. Brackets indicate the RC levels of A-D. Position of the limbs is represented by gray-colored areas. Scale bar: 100 µm. (J-M) Hoxc6-Hoxc10 expression and (J'-M') GFP expression in HH stage 15-17 embryos 20-24 hours after Gdf11 electroporation. The electroporated side is towards the bottom of the panels. Red and green arrows indicate the rostral limit of Hoxc6-Hoxc10 expression in the electroporated and the control side, respectively. Scale bar: 0.5 mm.