Unique chromatin modification patterns of the β-globin locus in primitive, EMP-derived fetal, and HSC-derived adult erythropoiesis. ChIP of modified histones (H3Ac or H3K4Me2) in the β-globin locus. Locations of amplimers are indicated by black bars in the diagram above and enrichments graphed in order below. Enrichment of H3Ac and H3K4Me2 was found in primitive erythroid cells from E11.5 peripheral blood (PB) in both embryonic and adult globin genes regions but only in adult genes in later fetal liver (E16.5 FL). E11.5 fetal liver had enrichment of modified histones over the adult genes and the βH1-globin gene but not εy-globin. Error bars represent the SEM and n = 3.