Fig. S3

GDP-fucose rescue of srn and morpholino knockdown of gmds. A. RT-PCR showed >80% of gmds transcript was mis-spliced after gmds morpholino (4 ng) injection. B–E. External phenotypes in srn and gmds morphants (E) include tail bend (compare B, wild type with C, srn) which is rescued after GDP-fucose supplementation (D). F–I. srn (G) and gmds morphants (I) showed reduced AAL staining compared to wild type (F) which is rescued after GDP-fucose supplementation (H). J–M. srn (K) and gmds morphants (M) showed increased Mauthner neuron number compared to wild type (J) a phenotype that is rescued after GDP-fucose supplementation (L). N–Q. srn (O) and gmds morphants (Q) showed reduced GFAP+ glia in the spinal cord compared to wild type (N), a phenotype that is rescued after GDP-fucose supplementation (P). R–U. srn (S) and gmds morphants (U) showed increased neuromuscular synapses compared to wild type (R), a phenotype that is rescued after GDP-fucose supplementation (T). Scale bar = 40 μm. In each experiment, at least 10 srn, normal siblings, gmds morphants or GDP-fucose rescued srn mutant embryos were assessed at 48 hpf. These results show that GDP-fucose rescues external and neural defects in srn mutants and that gmds knockdown by morpholino phenocopies srn phenotypes. Together, these further support the conclusions that gmds is the gene mutated in srn, that the fucose metabolism pathway is deficient in srn mutants, and that the resulting lack GDP-fucose is the cause of the srn mutant phenotypes, rather than the accumulation of the substrate, GDP-mannose.