a Blood counts from EDTA-stabilized whole blood of Rnaset2−/− and control mice revealed increased numbers of white blood cells (WBC, n = 19 Rnaset2−/− and n = 20 control animals) and reticulocytes (n = 13 Rnaset2−/− and control animals, respectively) in Rnaset2−/− mice accompanied by highly significantly reduced platelets (n = 19 Rnaset2−/−and n = 20 control animals) and hemoglobin (Hb) levels (n = 20 Rnaset2−/− and control animals, respectively). The mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly elevated (n = 20 Rnaset2−/− and control animals, respectively). Data depicted as the mean ± SEM. p values of two-tailed Student’s t-test are represented as ****p < 0.0001. b Blood smears of Rnaset2−/− and control mice clearly demonstrated the severe thrombocytopenia and the massive reticulocytosis (purple cells) in three biological replicates for control and Rnaset2−/−, respectively. Scale bar, 25 µm. c Bone marrow smear and immunohistochemical staining of d spleen and e bone marrow showed a higher density of CD41+ megakaryocytes, which presented dysplastic features demonstrated by single, small, and round nuclei and megakaryocyte agglomerations. Spleen and bone marrow images are representative of three independent experiments, scale bar, 100 µm. Bone marrow smear images are representative of four biological replicates for control and Rnaset2−/−, respectively, scale bar, 20 µm. f Depicted values of clinical chemistry from serum samples of Rnaset2−/− (n = 11 animals) and control (n = 16 animals for ALT and LDH and n = 13 for uric acid and protein) mice were significantly altered, whereas further parameters measured remained unremarkable. Data depicted as the mean ± SEM. p values of two-tailed Student’s t-test are represented as **p = 0.0027, ****p < 0.0001. ALT alanine aminotransferase, LDH lactate dehydrogenase. g Representative fluorescence microscopy image with a positive antinuclear antibody (ANA) indirect immunofluorescence test (IIFT) of Rnaset2−/− mouse serum (12 weeks old) with a titre of 1:10. Further titration even revealed a titre of 1:1000 for autoantibodies present in this serum. Scale bar, 50 µm. p values are represented as ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05 and not significant p ≥ 0.05. Source data are provided as a Source data file.