FIG. 1.

Map of the murine PU.1 gene transgenic constructs. The top diagram is a kilobase marker for reference, and below it are diagrams of the DNase I hypersensitive sites detected in the myeloid cell line 416B and T-cell line BW5147 as previously described (29). Diagrams of the murine PU.1 genomic locus, showing the location of the five coding exons and restriction sites for BamHI (B), HindIII (H), PstI (P), and EcoRI (E) and diagrams of the two transgenic constructs used in these studies are shown below. The first construct contains a 3.4-kb HindIII fragment from the kb −14 region, referred to in this paper as the kb −14 URE (upstream regulatory element), and a 2.1-kb PU.1 promoter fragment which includes 166 bp of 5′ untranslated region (9, 29), followed by a Thy1.1 cDNA as a reporter and a truncated 2.1-kb human growth hormone N gene (hGH-N). The second construct contains the identical PU.1 regulatory elements followed by the PU.1 cDNA, EGFP reporter, and a rabbit globin fragment to provide splice donor-acceptor sites and a polyadenylation signal.