Fig. 1

Gro binding is highly dynamic. a Analysis of Gro binding sites: Gro ChIP-seq was carried out in duplicate on 1.5–4 h, 4–6.5 h, and 6.5–9 h embryo collections. Putative binding sites (ChIP-seq peaks) were identified as described in Materials and Methods. The Venn diagram indicates overlap between binding sites at the three time points analyzed. b Clustering of Gro binding sites by temporal pattern. The majority of Gro binding sites are unique to a single time point, while many were observed at all three time points. Although a substantial fraction of sites overlap between time points 2 and 3, very few overlap between time points 1 and 2. A small number of sites (38) are bound in only time points 1 and 3 without being bound in 2, indicating that loss of Gro from a locus tends to be a permanent regulatory decision. c Analysis of Gro-bound genes: Each Gro binding site was assigned to the closest gene. The Venn diagram indicates overlap between Gro bound genes at the three time points analyzed. d Distribution of the number of Gro binding sites per gene: About 45% of all Gro-bound genes exhibit two or more distinct Gro binding sites peaks, a fraction that is greater than that expected by chance (p < 10⁻¹⁰ by Monte Carlo simulation)