Fig. 1. Expression and chromatin structural changes in a 54 kb region containing the FR gene, β-globin gene and chicken olfactory receptor gene in cell lines derived from different erythropoietic stages and a non-erythroid cell. In the cells or cell lines listed, + or – indicates whether the gene in the map below is expressed or silent, respectively. P or A indicates the presence or absence of DNase I-hypersensitive sites. A scale map of the FR gene, condensed chromatin region, β-globin domain and chicken olfactory receptor gene is shown at the bottom. The locations of hypersensitive sites (HSA, HS4 and 3′HS) are indicated by large arrows. ‘Taqman probes’ denotes the name and location of primer pairs and Taqman probes used for analysis.