Mll3 sustains a leukemia-resistant state in myeloid-primed ME-expressing postnatal progenitors. (A) Kaplan-Meier survival curves for recipients of Tet-Off-ME; Mll3Δ/Δ P0 liver cells after fetal ME induction. (B-C) Kaplan-Meier survival curves for Tet-Off-ME; Mll3+/+ and Tet-Off-ME; Mll3+/− mice after fetal or postnatal ME induction. (D) UMAPs representing CITE-seq profiles for P28 LK cells from control, Tet-Off-ME; Mll3+/+, and Tet-Off-ME; Mll3Δ/Δ mice. Cluster annotations were assigned based on Symphony alignment to the data shown in Figure 2A. (E) MLL::ENL transgene expression in HSC/MPP cluster 19. (F) Percentages of cells for each genotype in clusters 19, 22, and 12. (G) Distribution of myeloid identity scores in all cells along the HSC/MPP to GMP/neu trajectory, as calculated by quadratic programming. ∗∗∗P < .001 by Wilcoxon signed-rank test. (H) Volcano plots showing normalized enrichment scores and false discovery rates for Hallmark gene sets, as calculated from 4 pseudoreplicates per genotype for the HSC/MPP and pGM/GMP populations. (I) Expression of Pbx1, Ppic, and Il11ra1 in HSC/MPP clusters at P28 after fetal ME induction. ∗∗∗P < .001 by Wilcoxon signed-rank test. (J) Approach to mutagenize Mll3 in HSCs/MPPs and GMPs from P28 Tet-Off-ME mice after postnatal induction. (K-L) Kaplan-Meier survival curves for recipients of Tet-Off-ME HSCs/MPPs (K) or GMPs (L) after targeted mutagenesis of an intragenic region on chromosome 8 or Mll3. For all survival curves, group sizes and P values are shown in the panels. P values are indicated and were calculated by the log-rank test. Ctl, control; CPM, counts per million; gRNA, guide RNA; NES, normalized enrichment score; UMAP, uniform manifold approximation and projection.
