GDF6 knock down causes a loss of Pax6 expression as detected by in situ hybridization. Representative stage 20 embryos injected with 50 ng standard MO (A, D), 20 ng GDF6 MO (B, E), and 50 ng GDF6 MO (C, F). The injected sides are labelled i. Dorsal views show a loss of Pax6 stain within the two rhombomere bands in the hindbrain in the 20 ng GDF6 MO injected embryos (B), and an additional more severe loss of dorsal neural tube staining in the 50 ng GDF6 MO injected embryos (C), compared to the uninjected side (red arrows indicate rhombomeres) and standard MO injected embryos (A). Frontal views show a laterally reduced size of the Pax6 domain (E and F, injected side), compared to Pax6 staining in uninjected side (definition between forebrain and retinal stain indicated with white arrow) and standard MO injected embryo (D). (G, H) Dorsal and lateral views of stage 27 embryos injected with 25 ng of GDF6 MO show a reduced size of the Pax6 domain within the retina and a complete loss of stain within brain on the injected side. (I) Graph showing the percent stage 20 embryos injected at 20 ng and 50 ng of GDF6 MO and Standard MO showing a disruption of normal Pax6 stain.