Activated Notch1 promotes differentiation of the common lymphoid progenitor and favors lymphoid over myeloid lineage in vivo.

(A) Bone marrows of competitively repopulated animals were stained for IL-7R, lineage markers, c-kit, and Sca1, 8 months after transplantation. Plots represent fluorescence intensity for lineage markers on the x-axis and IL-7⁻R on the y-axis in the GFP⁺ cell population of the bone marrow of 2 representative animals transplanted with control vector-transduced cells (MSCV-GFP) or cells expressing activated Notch1 (MSCV-ICN/GFP). Numbers in corners represent percent of events within that quadrant. (B) Bone marrow of competitive repopulated animals were stained for differentiation markers (Gr-1, Mac-1, Ter119, and B220) and separately for Sca1 and lineage markers and analyzed by flow cytometry 5 months after transplantation. The absolute number of differentiated cells was then equalized to the absolute number of Sca1⁺lin⁻ cell in the same animal. Chart shows the fold increase of absolute number of differentiated cells per Sca1⁺lin⁻ stem cell in the bone marrow of animals transplanted with Notch1 overexpressing cells (MSCV-ICN/GFP) in comparison to controls (MSCV-GFP).