(A) Schematic of experimental design. Sex-matched 6–8 weeks old Ctrl (Rptor F/F) and cKO (Rptor F/F, Mx1-Cre) mice were treated with pIpC for seven times. The phenotypes were analyzed on day 7 or day 30 after the complement of pIpC treatment. (B) Representative flow cytometric analysis of myeloid cells from mice BM by CD11b and Gr-1 on day seven after pIpC treatment. Similar data were obtained on day 30. (C) Frequencies of various hematopoietic cell populations in BM based on CD11b and Gr-1 markers. n = 7 for Ctrl mice; n = 9 for cKO mice. Data are pooled from three independent experiments. (D) Expansion of lymphoblast population in cKO BM revealed by histology. Left, H&E staining showing prominence of cells with lymphoid morphology in the cKO BM; Right, normal BM histology from Ctrl mouse showing normal myeloid and erythroid lineages. Scale bar, 20 μm. (E) Expansion of lymphoblast revealed by cytology. Left, cytological preparation of BM smear from cKO mouse showing preponderance of lymphocytes (short arrows) and severe depletion of myeloid and erythroid lineages. There were some promyelocytes and myelocytes present (larger cells) but no mature neutrophils. Right, normal cytological preparation of BM from Ctrl mouse. There were numerous erythroid precursors with intensely basophilic, condensed chromatin (arrowheads) and a few lymphocytes (short arrow) with less condensed chromatin. Additionally, in Ctrl BM there were numerous mature neutrophils (ringed nucleus with constrictions) which were severely depleted in the cKO mouse. Scale bar, 10 μm. (F) Giemsa staining of FACS-sorted Rptor-deficient CD11b+Gr-1- BM cells. Scale bar, 10 μm. Similar morphology was observed in three independent experiments. (G) Principal component analysis (PCA) of gene expression in CD11b+ Gr-1- BM cells (IMLECs) and other hematopoietic cells. Numbers along axes indicate relative scaling of the principal variables. RNA-seq data from IMLECs obtained in our study were compared with those deposited in public database by others. Datasets are from known lymphoid (Pro-B, Pre-B, Naïve B, CD4 T, CD8 T, Treg and NK) or myeloid (macrophage, dendritic cell, granulocyte, neutrophil, eosinophil, basophil and erythrocyte) subsets.