SCD mice have 4.5-fold more total mononuclear cells, a marked increase in nucleated RBC content, and significantly altered lymphocyte distributions. A–F: Groups of C57BL/6 (n = 5), hemizygous (Hemi; n = 6), and SCD (n = 4) mice are euthanized and their spleens are removed. Single-cell suspensions are isolated from the spleens and stained with May-Grünwald stain. Total numbers of mononuclear cells in the spleens are determined by a hemocytometer. The individual proportion of mononuclear cells (both leukocytes and nucleated RBCs) is determined by a manual differential. Lymphocytes are identified by flow cytometry. Bars represent mean ± SEM percentages. Significant differences are determined by one-way analysis of variance with multiple pairwise comparisons between groups using the Newman-Keuls post hoc test. *P < 0.05, **P < 0.01, and ***P < 0.001.