Fig. 1

Fig. 1

a Thirteen different human embryonic sites were sampled for RNAseq¹⁵ and ChIPseq, as described in the “Methods” and in Supplementary Data 1 and 2. The same colour coding for each tissue is applied throughout the paper in overlaid ChIPseq tracks. The heart (left ventricle) dataset is summarised as Heart/LV from hereon. b 300 kb locus around the NKX2-5 gene, the most discriminatory TF gene for human embryonic heart¹⁵. The locus contains five unannotated human embryonic (HE) transcripts enriched in heart [three LINC RNAs and two transcripts of uncertain coding potential (TUCP)]. Heart/LV-specific (red) H3K4me3 and H3K27ac marks were detected at the NKX2-5 TSS and adjacent transcripts (HE-TUCP-C5T408 and HE-LINC-C5T409). Embryonic heart-specific H3K27ac marks were visible up to 200 kb away (e.g., at the extreme right of panel). H3K27me3 marked the region from NKX2-5 to HE-LINC-C5T409 in all non-heart tissues (the track appears black from the superimposition of all the different colours other than red). ENCODE data are from seven cell lines²⁶. c Genome coverage by ChromHMM for the different histone modifications was similar across all tissues (Supplementary Fig. 1) with an average 89.8% of the genome unmarked (range: 81.7–94.0; States 4 & 5), and 3.3% consistent with being an active promoter and/or enhancer (range: 1.7–6.1; States 1–3).