MPPs seed the BM and give rise to CLPs. BM from femurs of the MPP and CLP recipients in the time courses (Figure 2) were pooled and stained to reveal donor chimerism and populations. Plots are from 1 time course experiment and are representative of 2 experiments. A total of 2.5 × 106 events were collected from each sample. Arrows in the top panels indicate gating hierarchy. The far left plots are gated on donor-derived cells, and the various numbers of events in each plot reflect variable donor chimerism. Whereas CLPs do not self-renew appreciably, MPPs do give rise to more Flk2+CD27+ cells, including both MPPs and CLPs.