Fig. 3. Cardiovascular, but not other neural crest-dependent, derivatives are affected by loss of endodermal Shh. Comparison of wild-type, Nkx2.5^Cre/+; Shh^flox/- and Shh^-/- embryos reveals that only certain NCC-derived structures depend on endodermal Shh. (A-F) Cranial nerves (CN) are relatively normal in Nkx2.5^Cre/+; Shh^flox/- embryos (B) compared with Shh^-/- mutants (C), whereas their arch-artery patterning (E) more closely resembles Shh^-/- defects (F) rather than wild-type (A,D). (G-O) Similarly, expression of the NCC markers Ap2 and CrabP1, as well as AP2 antibody, in Nkx2.5^Cre/+; Shh^flox/- mutants (H,K,N) resemble wild-type (G,J,M) and not the abnormal pattern seen in Shh^-/- embryos (I,L,O). In all panels, arrows and arrowheads mark abnormal and normal findings, respectively, in mutants as compared with control embryos.