NUP98-TOP1 expression leads to in vivo myeloproliferation. (A) NUP98-TOP1 leads to in vivo proliferative advantage as assessed by increased peripheral blood GFP⁺ content at various times after transplantation. Graph is representative of 4 independent experiments with at least 4 mice in each group (mean ± SD; GFP CTL [□]; NUP98-TOP1 [▪]). (B) NUP98-TOP1 leads to a progressive increase in PB white cell counts. Results are shown for individual mice in a representative experiment. Median values are depicted with a horizontal line. Open symbols indicate GFP CTL mice; filled symbols, NUP98-TOP1 mice. (C) Differential counts performed on Wright-Giemsa-stained PB smears of mice at 2 (top) and 6 (bottom) months after transplantation. Counts are the average of 3 or 5 CTL GFP or NUP98-TOP1 mice, respectively. ▧ indicates lymphoid cells; ▪, myeloid cells. (D) Representative experiment depicting PB of 5 mice stained with antibodies to Mac-1 and B220 at 2 months (top panel) and 6 months (bottom panel) after transplantation. ▪ represents transduced (GFP⁺) cells; ▧, GFP^-. Mice 1 to 5 are GFP CTL; mice 6 to 10 are NUP98-TOP1. (E) Representative Wright-Giemsa-stained PB smear of NUP98-TOP1 mouse at 6 months after transplantation. Original magnification, × 1000. See Figure 5B for control.