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Fig. 3 Elevated levels of Hh signaling impair RA-mediated induction of ectopic endocrine pancreas in the anterior endoderm. (A-O) Dorsal views (anterior to left) of pdx1 (A-C), insulin (D-F), neurod (G-I) and hhex (J-L) expression at 24 hpf and ptf1a (M-O) expression at 48 hpf, comparing embryos transiently treated from 9-10 hpf with DMSO (A,D,G,J,M), retinoic acid (RA; 1 μM) (B,E,H,K,N) or RA plus purmorphamine (25 μM) (C,F,I,L,O). Brackets indicate ectopic expression and arrowheads indicate endogenous expression. The number of embryos displaying similar expression patterns is indicated in each case. (P) qPCR of pdx1 expression at 24 hpf in DMSO-, RA- and RA plus purmorphamine-treated embryos (error bars show s.e.m.). Asterisks indicate a significant change (at least 2 s.d.) compared with control.