Abnormal development of hematopoietic progenitor cells in Trim28 mutant mice. Adult TMC [Trim28^flox/flox:Tg^Mx1Cre (flox/flox:Mx1Cre)] mutant or control [Trim28^flox/flox (flox/flox) and Trim28^flox/+:Tg^Mx1Cre (flox/+:Mx1Cre)] mice at ages 5 to 6 weeks were injected with poly(I:C). (A) Flow cytometric analysis of total bone marrow cells and division into individual early progenitor compartments (shown on the right) according to cell surface expression of cKit, Sca1, FcγR, CD34, and lineage (Lin) markers. Numbers in the boxed areas indicate the mean percentages of cells in the gated area calculated by dividing the number of cells in that subpopulation by the number of cells in its immediate ancestor population (Frequency of Parent in FlowJo software). (B) The absolute number of HSC/MPP, CMP, MEP, and GMP was calculated from the data shown in panel (A) and total bone marrow cell number. Averages are indicated with SEM. * indicates statistically significant, P < .05. NS: not significant, P > .05. (C) The absolute number of Mac1⁺ cells in the bone marrow of mutant and control mice. (D) The absolute number of cKit^hi Lin^- and cKit^hiLin⁺ cells in the bone marrow of control and conditionally mutant mice. (E) The absolute number of cKit^hiCD71^hiTER119^-, cKit^hiCD71^-TER119^-, and cKit^hiTER119⁺ cells in the bone marrow. The lineage mixture used for panels (A, B, and D) includes antibodies that recognize TER119, Mac1, Gr1, B220, CD19, CD5, CD4, and CD8a. Mice were analyzed for 2 weeks (A, B, D, E) or for 2 and 4 weeks (C) after completion of poly(I:C) administration. The data represent a summary (B-E) or are representative (A) of more than 3 mice of each genotype from 2 to 3 independent experiments. Each circle represents an individual mouse, and the black bars represent averages.