Figure 1.

Conditional AE expression alters normal blood cell development.

1. DOX-dependent AE and GFP expression.

2. Conditional GFP expression in blood stem and progenitor cells. Green bars represent the percentage of GFP-expressing cells ± SD in each lineage. Shown are mean values for four R26/AE BM-reconstituted recipients that had been DOX exposed during 10 days. LT-/ST-HSC, long-term/short-term repopulating haematopoietic stem cells; CMP, common myeloid progenitor; GMP, granulocyte macrophage progenitor; MEP, megakaryocyte erythroid progenitor; CLP, common lymphoid progenitor.

3. Blue bars show mean AE mRNA levels ± SD from three compound R26/AE mice in the absence (−DOX) or after 3 days of DOX exposure (+DOX). AE mRNA was determined in BM, L⁻K⁺S⁺ cells, CMP, GMP, MEP, B220⁺ B-lymphoid cells, CD3⁺ T-lymphoid cells, Ter119⁺ erythrocytes, CD41⁺ megakaryocytes, CD11b⁺ monocytes and macrophages and Gr1⁺ myeloid cells. AE levels are represented relative to AE mRNA transcription in the Kasumi-1 cell line (white bar).

4. Peripheral blood films from a representative control and an AE-expressing mouse. Arrowheads indicate abnormal red blood cells.

5. Above the bar diagram a spleen (SPL), thymus (THY) and lymph node (LN) of a non-induced (left) and an AE-expressing mouse (right) are shown. Each bar represents the mean weight ± SD for five individual mice. White bars represent non-induced and black bars AE-expressing mice. Two-tailed unpaired t-test analysis demonstrated significant differences in spleen (p = 0.0331), thymus (p = 0.0021) and lymph node (p = 0.0093) weight between control and AE-induced mice.

6. Flow cytometric analysis of erythroid, granulocytic, magakaryocytic, B- and T-cell maturation profiles from controls (white bars) and mice that have been DOX-induced (black bars, +DOX nine months). For each cell type the absolute percentages ± SD of cells in the BM or the thymus are shown. Roman numerals designate different stages of erythrocyte maturation: I, proerythroblasts; II, basophilic erythroblasts; III, late basophilic erythroblasts and chromatophilic erythroblasts; IV, orthochromatophilic erythroblasts and reticulocytes. 7AAD, 7-amino-actinomycin D; DN, double negative and DP, double positive for CD4 and CD8 surface markers. * p < 0.05; ** p < 0.01; **** p < 0.0001; ns, not significant.