A,B,C,D ptc1 expression in wild-type (A), ptc1/+ (B), ptc1 mutant (C) and ptc1;ptc2 mutant (D) stained in a single reaction 19 somite stage; no significant increase is detectable in ptc2 mutants at this stage. E,G,I,K,M,O,Q,S,V,W,X) wild type embryos; F,H,J,L,N,P,R,T,U,Y) ptc1;ptc2 mutants. E,F) 21 somite stage; Gli expression is increased ptc1;ptc2 mutants. G,H) foxa1 expression labels medial and lateral floor plate and is expanded in ptc1;ptc2 mutants, shh a medial floor plate marker, remains unchanged (inset). I,J,K,L) 18 somite stage; pax2 labeling of the optic stalk in wild type (I) is expanded in ptc1;ptc2 mutants (J). At the same time pax6 expression in the optic cup is severly reduced in ptc1;ptc2 mutants (K,L). M,N) 12 somite stage, flat mount, dorsal view; skeletal muscle alpha actin1, a marker for muscle differentiation is increased in ptc1;ptc2 mutants. O,P) 20 somite stage, ventral part of anterior somites. Presumptive migratory myoblasts that will form fin muscle express lbx1. Expression of this gene is lost in ptc1;ptc2 mutants. Q,R) Oblique view on wnt2b expression focusing on region between lateral plate and ventral somites 21 somite stage. This gene is required for fin bud formation and is still expressed in ptc1;ptc2 mutants. S,T) 10 somite stage, flat mount, dorsal view. Initial expression of tbx5 in the -then continuous- heart and pectoral fin primordium is unaltered in ptc1;ptc2 mutants (arrowheads). Double mutants lack tbx5 expression in the optic cup (star). U,V,W,X,Y) 10 somite stage flat mount dorsal view U,V) ptc1;ptc2 mutants and wild-type show tbx5 labeling at the edge of the lateral plate mesoderm, ptc2 is also expressed in this region (W). ptc1 expression is normally only detectable in the somites strongly in the adaxial cells and weakly in the lateral somite. However, ptc1 is upregulated throughout the entire embryo in ptc1;ptc2 mutants, showing that it can respond to Hh signaling in lateral plate mesoderm. Note: X and Y were stained for equal time is the same reaction.
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