Fig. 7.

Pax7 and Pax3 are essential for hindbrain and neural crest patterning. The early phenotype of Pax7 morphants was analyzed at stage 18. Control siblings show normal expression of krox20 (A) and snail2 (F). Pax7 morphants exhibit either a severe loss of krox20 (B) and snail2 (G), or a posterior shift of rhombomeres r3 and r5 (C, arrows) accompanied by reduced snail2 expression (H). A similar phenotype is observed in Pax7EnR injected embryos (D, I) or Pax3 morphants (E, J). Pax7MO phenotype is rescued by injection of Pax7-myc mRNA), insensitive to the morpholino (Fig. 6): snail2 expression is restored (L shows two morphants and (M) two siblings injected with MO and the rescue construct).