Figure 4

GDF6 knockdown disrupts neural differentiation. At neurulation stages, immunostaining for neural cell adhesion molecule (NCAM) is lost or reduced in intensity in the GDF6 MO injected side: A(i), C(i), D, F(i), H(i), I. (A) Stage 24 embryo injected with 50 ng GDF6 MO showing complete loss of NCAM stain along the neural tube on the injected side. Some patchy retina stain remains. This embryo is also curved and appears to be reduced in size on the injected side. (B) Normal NCAM stain in an embryo injected with 50 ng standard MO. (C) Stage 24 embryos injected with 20 ng GDF6 MO with NCAM stain lost along the posterior neural tube (top embryo, arrow marks posterior end of NCAM stain), or along the entire neural tube (bottom embryo). (D, E) Injected (D) and uninjected side (E) of bottom embryo in (C) showing patchy loss of NCAM stain in the retina of the injected side. (F) Dorsal view of stage 27 embryo injected with 50 ng GDF6 MO. The injected side (i) shows a loss of NCAM stain both along the neural tube and within the head and retina. In the head and retina small patches of intense NCAM staining remain. (G) Normal NCAM staining in a stage 27 embryo injected with 50 ng standard MO. (H, I) Full view and close up of a stage 27 embryo injected with 20 ng GDF6 MO. Neural tube NCAM staining is less intense on the injected side (top half of embryo). (J) Percent embryos with NCAM reduction on the injected side following GDF6 MO injection.