Fig. 3. Loss of Shh/Ptc1-signaling does not inhibit or promote neuron differentiation. (A,B) HH stage 11/12 chick embryos electroporated with Ptc1^loop2, were analyzed 24 hours later for GFP expression (green) and molecular markers for neural differentiation (red). (A) Immunostaining with the Tuj1 antibody (red) revealed the presence of Ptc1^loop2-transfected cells expressing Tuj1 (arrows indicate co-expressing cells). (B) Immunostaining with NeuN revealed the presence of transfected cells expressing NeuN (yellow cells). (C,D) Loss of Shh/Ptc1 signaling causes cell fate changes 24 hours PE. (C) At 12 hours PE of Ptc1^loop2, Pax7 expression is comparable on both sides of the neural tube. (D) At 24 hours PE, Pax7 expression is ventrally induced on the transfected side of the neural tube.