Fig. 4

Ectopic ALK6 can substitute ALK3 knock-down in dorso-ventral patterning. Embryos were injected laterally in one dorsal blastomere at the 4-cell stage with 0.8 pg of ALK3 or ALK6 MOs and, for rescue experiments, co-injected with 50 pg of alk3 RNA or alk6 RNA. A lacZ plasmid was co-injected to identify the injected side, embryos were cultured till stage 18 and stained for LacZ. The neuroectoderm was visualized by in situ hybridization against the pan-neural marker gene sox2. Embryos were categorized according to expanded or reduced sox2 expression and differences between indicated groups were analyzed using the Χ ² test. Statistically significant deviations (p-value < 0.01) are indicated by double asterisks; n.s.: not significant. a Representative images of ALK3 morphant embryos and the corresponding rescue experiments are shown. Embryos were injected as indicated; asterisks indicate the injected side. b Results from at least three independent experiments are summarized in the graph. c Representative images of ALK6 morphant embryos and the corresponding rescue experiments are shown. Embryos were injected as indicated; asterisks indicate the injected side. d Results from at least three independent experiments are summarized in the graph