Developmental dichotomy of CLP1 and presumptive CLP2 progenitor cells evidenced by analysis of Gfi1−/− and Gfi1GFP/+ mice.

2007-03-21T00:33:22Z (GMT) by Chozhavendan Rathinam Christoph Klein

A) FACS plots indicating relative decrease of CLP1 (upper panels) and normal numbers of presumptive CLP2 (middle panels) in Gfi1−/− bone marrow cells. Cells were pregated on LinIL7Rα+ cells (upper panels) and LinIL7Rα+Sca1+CD19 cells (middle panels), respectively. Bar diagrams indicating absolute numbers of CLP1 and CLP2 cells of Gfi1−/− and Gfi1+/+ mice (lower panel, n = 3 mice). Lineage markers included CD4, CD8, CD11c, CD11b and B220. Flow-cytometric analysis was performed on pooled BM cells from 5 mice. Shown is a representative experiment of 3. B) FACS plots indicating relative increase of ETP in Gfi1−/− thymus. LinCD25CD44+ cells (upper panels) were gated (G1) and analysed for expression of c-kit and IL7Rα (lower panels). Experiments were performed on pooled thymi (n = 5 mice). Bar diagrams indicating absolute numbers of ETP of Gfi1−/− and Gfi1+/+ mice (lower panel, n = 3 mice). The total number of thymocytes was decreased by ∼6 fold in Gfi1−/− mice. Shown is a representative experiment of 3. C) Transcriptional activity of Gfi1 locus in hematopoietic progenitor cells and thymic B cells. Pooled bone marrow cells or thymocytes (n = 5) were analyzed for GFP expression in the following populations: LSK (HSC), LinIL7Rα+Sca1lowc-kitlow (CLP1), LinIL7Rα+Sca1+c-kitB220+CD19 (CLP2) and LinCD25IL7RαCD44+c-kit+ (ETP). Shaded histograms represent GFP fluorescence in Gfi1+/GFP cells, open histograms represent autofluorescence of Gfi1+/+ cells. The GMFI (Geo Mean Fluorescence Intensity) of Gfi1+/+ (above) and Gfi1+/GFP (below) cells is indicated. Data are representative of 3 independent experiments.