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Fig. S6 Shh controls the timing of proneural gene induction within the Th. At the 10-somite stage, application of the Shh agonist purmorphamine leads to the strong activation of neurog1:RFP (a and b). Conversely, application of the Shh antagonist cyclopamine leads to the severe down-regulation of neurog1:RFP in the caudal thalamus (c). Analysis of smu mutant embryos shows a strong down-regulation of the proneural genes neurog1 and ascl1a in the entire thalamic complex at 33 hpf (d, e, g, and h). Asterisks mark an independent neurog1 expression domain within the basal MDO territory. At the same stage, her6 expression is still detectable in the diencephalon of smu mutant embryos, suggesting a Shh independent maintenance mechanism for her6 mRNA (f and i). cTh, caudal thalamus; MDO, mid-diencephalic organizer; PTec, pretectum; PTh, prethalamus; rTh, rostral thalamus; Tec, Tectum.