Expression of transgene in each rescued mouse.

(A) RNA blot analyses of rescued GATA-1.05 compound mutant mice. Total cellular RNA was extracted from the spleens of G1R (line No. 782), G2R (line No. 620), G3R (line No. 390), or WT mice. The transcript sizes of endogenous and transgenic RNA transcripts are as follows: endogenous GATA-1 (G1-end) is 1.9 kilobases (kb); transgene (G1 Tg) of GATA-1 is 2.1 kb; endogenous GATA-2 (G2-end) is 3.5 and 2.9 kb; transgene (G2 Tg) of GATA-2 is 2.3 kb; transgene of GATA-3 (G3 Tg) is 2.7 kb. A β-actin probe was used as the internal control. (B, C) Western blot analysis of G1R or G2R lines. To examine protein levels of transgene-derived GATA factors, splenic nuclear extracts prepared from various transgenic lines (indicated above the lanes) were subjected to Western blot analysis using anti–GATA-1 N6 monoclonal antibody (B) or anti–GATA-2 RC1.1 monoclonal antibody (C). For controls, nuclear extract from MEL cells (+) or IE3.9int-GFP mouse spleen was used. (D) EMSA of transgenic GATA factors. Radiolabeled GATA probe was incubated without (lane 1) or with splenic nuclear extracts from a WT mouse (lanes 2-3), G1R line No. 782 (lanes 4-6), G2R line No. 620 (lanes 7-9), and G3R line No. 390 (lanes 10-12) in the presence of cold GATA (lanes 3, 5, 8, 11) or mutated GATA (lanes 6, 9, 12) oligonucleotides. G1R and G3R were similar to WT, but G2R was significantly higher than WT.