Fig. 3. Expression of follistatin (Fst) in the neural tube causes caudal displacement of Hox protein 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 Fst electroporation. The electroporated side (on the right in all panels) is marked by GFP expression. White arrows indicate the caudal expression limits of Hoxc6 (A), Hoxc8 (B) and Hoxc9 (C) in the control sides. Yellow arrow indicates the rostral expression limit of Hoxc10 (D) in the electroporated side. Broken lines in A-D indicate the RC levels of sections (E-H). (I) A diagram depicts the normal Hox expression domains in the control (CTL) side and the caudal displacement of Hox expression domains in the Fst 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.