Zeb2^Δ/ΔMx1-Cre mice show characteristic features of myeloproliferative disease. (A) Representative images of spleens from Zeb2^Δ/ΔMx1-Cre and control mice at 8 weeks, 10 months, and 16 months after Poly(I:C) administration demonstrating progressive splenomegaly in Zeb2-deficient mice. Data are representative of at least 3 independent experiments. (B) Histological analyses of spleen sections show extensive loss of white pulp compartment in Zeb2-deficient mice. Data are representative of at least 3 independent experiments. Bar graphs, 1000 µm (top); 100 µm (bottom). (C) A significant increase in the appearance of LKS, LKS-SLAM, and MEP populations within the spleen of Zeb2^Δ/ΔMx1-Cre mice compared with controls indicate a relocation of hematopoiesis to the spleen. Data are from 6 biological replicates shown as means ± SEM. Unpaired, 2-tailed t test was performed to determine significance; ***P < .01. (D) Hematoxylin and eosin staining of BM sections demonstrate grouping of abnormal megakaryocytes (arrows) in Zeb2^Δ/ΔMx1-Cre mice. Bar graphs, 50 µm. (E) Silver staining shows the presence of reticular fibers in the BM space in Zeb2^Δ/ΔMx1-Cre mice. Bar graphs, 100 µm. (F) BM smears were subjected to Prussian Blue staining for hemosiderin demonstrating iron depletion in Zeb2^Δ/ΔMx1-Cre marrow cells.