Gfi-1−/− ST-HSCs and CMPs are partially rescued by reducing Id2 levels. (A) Flow cytometric analyses of Lin−/Sca-1+/c-Kit+ (LSK) and Lin−/Sca-1−/c-Kit+ (LK) BMCs for HSPCs. Representative flow cytometry plots indicating LT-HSCs, ST-HSCs, and MPPs in LSK identified by Flk2 and CD34 cell-surface markers and CMPs, MEPs, and GMPs in LK identified by FcRγII/III and CD34. (B) Bar graph showing the percentage of Lin− cells in light-density separation medium (LSM)-purified BMCs harvested from 2 femurs and 2 tibias of each mouse. The data are presented as the mean % ± standard deviation (SD). The percentages of Lin− cells are reduced in Gfi-1−/− mice compared with control mice. (C) Bar graphs showing the percentage of LK cells in Lin− BMC population. The data are presented as the mean % ± SD. (D) Total number of LT-HSCs, ST-HSCs, and MPPs in BMCs, which were obtained by multiplying the percentage Lin− and LSK cells in BMCs, the percentage of each subpopulation identified by Flk2 and CD34, and the total cellularity of 2 femurs and 2 tibias. The data are presented as the mean ± SD. *P < .05 for Gfi-1−/− compared with Gfi-1−/−;Id2+/− ST-HSCs. (E) Bar graph showing the percentage of CMPs, MEPs, and GMPs in LK population. Data are presented as the mean % ± SD. (F) Total number of CMPs, MEPs, and GMPs in BMCs, which were obtained by multiplying the percentage of Lin− and LK cells, the percentage of each subpopulation identified by FcR and CD34, and the total cellularity of 2 femurs and 2 tibias. Data are presented as the mean ± SD. (G) Bar graph showing total numbers of LT-HSC, MPP-1/2, MPP-3, and MPP-4 subpopulations, which were obtained by multiplying the percentages of Lin− and LSK cells in BMCs, the percentage of Flk2-positive or negative cells, the percentage of each subpopulation identified by CD150 and CD34, and the total cellularity of 2 femurs and 2 tibias. The graphs show data combined from 3 individual immunophenotypic analyses. The data are presented as the mean ± SD. *P < .05 for Gfi-1−/− compared with Gfi-1−/−;Id2+/− for MPP-3.