Downregulation of Sema6A in BCCs results in translocation of motoneurons out of the spinal cord. (a) In the absence of Sema6A from BCCs, motoneurons stream out of the ventral spinal cord and migrate along the ventral roots (arrows). The open arrow points to a motoneuron that is located in the ventral funiculus. (b) In control-treated embryos motoneurons along ventral roots or in the ventral funiculus were rarely seen. Motoneurons were identified by Isl-1 (red). An EGFP plasmid was co-injected with the dsRNA derived from SEMA6A. Axons were stained with an antibody against neurofilament (blue). Note that sensory neurons in the DRG (asterisk in (a, b)) are also stained by Isl-1. (c) Perturbation of Sema6B or Sema6D did not enhance the number of motoneurons in the periphery compared to control-treated embryos injected only with the plasmid encoding EGFP. Three asterisks indicate P < 0.0001 for the comparison between dsS6A and all other treatment groups. Values are given as mean ± standard error of mean. Bar: 50 μm.