Fig. 5.

Ectopic HS5 interferes with loop formation between the β-globin LCR and gene and establishes close proximity with endogenous HS5. (A) Chromatin from adult spleen was cross-linked with formaldehyde, digested with EcoRI, and re-ligated. After reversal of cross-links, ligation efficiencies between the anchor primer in the LCR HS2 to HS4 fragment and positions across the locus were determined. To compare results from different mouse lines, the data were normalized to an interaction in the mouse ERCC gene. The strongest cross-linking frequency was set to 1. (B) Chromatin from adult spleen was treated as above but was digested with Apo I and religated. The data were normalized to an interaction in the mouse CalR gene and the strongest cross-linking frequency was set to 1. See Table S4 for primer sequences. The results of multiple chromatin preparations with each enzyme are shown ± SEM. P < 0.01 when comparing proximity of the LCR to β-globin in WT versus HS5 mice.