Fig. 3. Activation of XNF-ATc3 generates neural CE defects and anterior truncations. (A) Xenopus embryos were injected at the one-cell stage with 100 pg (middle panels) or 500 pg (right panels) of CA XNF-ATc3. Embryos injected with 100 pg CA XNF-ATc3 resembled control embryos during gastrula stages (first row, vegetal view of stage 11; second row, vegetal view of stage 12.5), but developed neural tube CE defects in 31% of embryos at neurula stages (third row: dorsal view of stage 17). Embryos injected with 500 pg CA XNF-ATc3 exhibited slight defects at stage 12.5 and neural CE defects in 81% of injected embryos. Control embryos developed no neural CE defects. (B) Xenopus embryos were injected at the one-cell stage with 50 pg CA XNF-ATc3 and analyzed for Krox20, Eng, Pax3, Sox2 and HoxB9 expression at the neurula stage. For XAG-1 in situ hybridization embryos were injected with 250 pg CA XNF-ATc3 and 100 pg lacZ (red) for lineage tracing.