Flow cytometric analysis and progenitor colony assays of bone marrow and spleen. Mice were euthanized 25 weeks after starting tamoxifen. (A) Representative flow cytometry scattergrams showing the gating of erythroid precursors with CD71 and Ter119 antibodies. Region I, proerythroblasts; region II, basophilic erythroblasts; region III, late basophilic and chromatophilic erythroblasts; region IV, orthochromatophilic erythroblasts. (B) Histograms of the means of erythroid precursors ± SEM (n = 3 mice per genotype). (C) Numbers of erythroid progenitors assessed by colony assays in methylcellulose. BFU-E, burst forming unit erythroid. (D) Flow cytometry scattergrams showing the gating of megakaryocytic population with CD41/61 and CD42c antibodies. (E) Histograms of the means of megakaryocytic population ± SEM (n = 3 mice per genotype). (F) Numbers of megakaryocyte progenitors assessed by colony assays in collagen-based medium. CFU-Mk, colony forming unit megakaryocyte. (G) Representative flow cytometry scattergrams of granulocytes/monocytes using MAC1 and Gr1 antibodies. (H) Histograms of the means of MAC1/Gr1 double-positive myeloid progenitors ± SEM (n = 3 mice per genotype). (I) Numbers of myeloid progenitors assessed by colony assays in methylcellulose. CFU-G, colony forming unit granulocyte. Bone marrow and spleen from 2 mice per group were analyzed on duplicate plates. One-way or 2-way ANOVA with subsequent Bonferroni post-test was used, and *P < .05 is indicated.