FIGURE 1.

Contiguous deoxyguanosine residues located at 215–219 of the G1HE are critical for Gata1 gene reporter expression in transgenic mice. A, mouse Gata1 locus with two cell-type specific first exons (IT and IE), five coding exons (II–VI), and four cis-regulatory elements (G1HE, double GATA, CACCC, and GATA repeats). a–d, structures of the reporter constructs used for the transgenic mouse reporter assays. B, representative X-gal staining of fetal liver prepared from 1–235IE2.6LacZ and 1–207IE2.6LacZ transgenic embryos. C, top, sequence of the G1HE-(201–235) probe and the competitors (C1–C6) used for EMSA. The mutated residues of the competitors are shown in red. Bottom, the G1HE-(201–235) region was used as a probe in EMSA using K562 nuclear extracts. Binding reactions were performed using 3 μg of nuclear extract and probe either in the absence or presence of unlabeled competitors. A 100-fold molar excess of wild type (WT) and mutated competitors (C1–C6) were used. DNA-protein complexes are indicated as 1, 2, and asterisk (*).