Genome-wide analysis of Smad2 and FoxH1 binding sites in zebrafish blastula

Morphogen gradients expose cells to different signal concentrations and induce target genes with different ranges of expression. To determine how the Nodal morphogen gradient induces distinct gene expression patterns during zebrafish embryogenesis we characterized the binding sites of the Nodal-specific transcription co-activators Smad2 and FoxH1 in wild-type, Nodal-overexpressing or Nodal signaling inhibited embryos. We found that FoxH1 binds to Nodal targets loci even in the absence of the signal, while Smad2 only binds and colocalizes to FoxH1 upon induction of the Nodal pathway. Overall design: 6 samples total.