Figure 2.

Neither Wnt5a nor Wnt7a is expressed in a gradient along the anteroposterior axis of the chicken lumbosacral spinal cord. A–H, Open-book preparations (A, E) and transverse sections (B–D, F–H) of HH26 spinal cords were used for in situ hybridization analyses of Wnt5a (A–D) and Wnt7a (E–H) expression. No gradient was detectable for Wnt5a mRNA in the floor plate of the lumbosacral region (supplemental Fig. S5, available at www.jneurosci.org as supplemental material), although slightly higher levels were found at the thoracic level (data not shown). Expression of Wnt5a in motoneurons is restricted to lumbosacral levels of the spinal cord. No gradient was observed for Wnt7a in the area adjacent to the floor plate (F–H, open arrowhead). Arrows in A and E indicate levels of transverse sections shown in B–D and F–H. Scale bars: (in H) B–D, F–H, 50 μm; (in E) A, E, 500 μm.