We next tested for a spinal motor neuron phenotype, since both mouse and human show loss of this class of neurons with CLP1 mutations. Zebrafish larvae were fixed at 72 hpf and stained with the motor neuron marker Sv2 (Boon et al., 2009). Specifically in the clp1 p.R44X mutants, we found altered motor neuron morphology with full penetrance (Figure S3C), similar to established zebrafish motor neuron mutants (Fassier et al., 2010).
