Mice with mDia1 deficiency showed granulocytopenia at young ages. (A-C) Relative DIAPH1, RELL2, and RNF145 mRNA expressions in CD34⁺ bone marrow cells of patients with or without chromosome 5q deletion. Control: samples from orthopedic surgery, N = 17; 5q− syndrome: sole 5q deletion, N = 17; del(5q): del(5q) MDS with other cytogenetic abnormalities, N = 21; other: MDS with cytogenetic abnormalities other than del(5q), N = 18; normal cyto: MDS without cytogenetic abnormalities, N = 19. Data were obtained from a microarray gene expression analysis (Gene Expression Omnibus accession number: GSE19429). (D) Western blot analysis of total bone marrow cells from the indicated mice. (E) Peripheral blood absolute neutrophil, eosinophil, and basophil counts from mDia1 wild-type (WT, N = 8), heterozygous (Het, N = 11), and knockout (KO, N = 19) mice. All the mice were aged between 6 and 8 weeks. (F) Complete blood count (CBC) of indicated lineages as in panel E.