Figure 1. Robos are expressed by spinal motor neurons.
(A–F) Islet-1 and β-galactosidase antibody labeling on Robo1lacZ/+ and Robo2lacZ/+ E10.5 spinal cord sections (n=4 embryos for each genotype) showing Robos are expressed by spinal motor neurons. (G, H) Robo1 and Robo2 antibody labeling on wild-type E10.5 spinal cord sections. (I, J) Robo1 and Robo2 antibody labeling with Islet-1 on dissociated spinal motor neurons from the wild-type E10.5 spinal cords. (K–M) Islet-1 labeling combined with in situ for Slit1 mRNA in E10 spinal cord sections. Islet-1+ motor neurons settle just outside the Slit1-expressing floor plate. (N) In situ for Slit2 mRNA in E10 spinal cord sections showing Slit2 is expressed in the medial floor plate and spinal motor neurons. Scale bars: A–H, 50 μm; I, J, 20 μm; K–N, 20 μm. MN, motor neuron; FP, floor plate.