Fig 1.

Organization of the murine β-globin locus. The locus contains two embryonic/fetal (Ey and βH1) and two adult (βmajor and βminor) β-globin genes. Hypersensitive site 2 (HS2) resides 40 and 54 kb upstream of the βmajor and βminor promoters, respectively. The β-globin genes are depicted as boxes, and HSs are depicted as circles. Bars below the locus depict hyperacetylated zones defined by ChIP analysis with anti-acetylated H3 and H4 antibodies in MEL cells and in 14.5 days postcoitum (dpc) fetal liver (32). GATA-1 and NF-E2 crosslinking data, derived from ChIP analysis in MEL and G1E-ER-GATA-1 cells, are also depicted (40). Large +, strong crosslinking; small +, weak crosslinking; −, no or very weak crosslinking.