Apoptosis and gene expression of TER-119⁺ cells.

(A) Forward-light scatter (FL1-H) vs PE-TER-119 staining of single TER-119⁺ cells purified from wild-type and GATA-1^low mice by immunomagnetic adsorption. The purity of the TER-119⁺ cells was 97% and 95%, respectively. (B) Propidium iodide (top) and propidium iodide–TUNEL double staining (bottom) of the TER-119⁺ cells purified in panel A (25 × magnification except for the small quadrants in the bottom panel, which are 40 × magnification to show the details of the apoptotic nuclei). (C) Semiquantitative RT-PCR analysis of the expression of β₂-microglobulin (as control), β-globin, GATA-1, and GATA-2 in the TER-119⁺ cells purified from the spleens of wild-type (left) and GATA-1^low (right) mice. Each product was analyzed for increasing numbers of cycles as indicated by a triangle on the top of the panels. In particular, the products were analyzed after 18, 21, 24, and 27 cycles for β₂-microglobulin; 15, 18, 21, and 24 cycles for β-globin; and 20, 24, 26, and 30 cycles for the total GATA-1 and GATA-2 transcripts.