Fig. 3: B progenitor compartment is unaffected by postnatal induction of KMT2A::AFF1.

A Schematic illustration of postnatal induction of KMT2A::AFF1 by administration of Doxycycline (Dox) food to the female from approx. day 5 to 18 of pregnancy. KMT2A::AFF1 expression was analyzed after ∼6-weeks and phenotype at 8–30 weeks. B Relative expression (normalized to B-actin) of KMT2A::AFF1 in purified HSCs, LMPPs, PreProBs (CD24^-/+) and ProBs in bone marrows (BMs) from ∼6-week-old mice, treated with Doxycycline as shown in panel (A) (1 FACS experiment). C Frequencies of LSK, HSCs and LMPPs as percent of CD45⁺ cells in control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice (6 experiments, n_males = 7; n_females = 18). D Flow cytometry plots of LSK compartment in control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice. Numbers are mean percentages of total CD45⁺ cells. E Single HSCs were co-cultured on OP9 stroma. Frequency of colonies (left) and linage output (right) for control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice are shown. Colony distribution defined as B (CD19⁺B220⁺), myeloid (CD11B⁺GR1⁺); B and myeloid (B & My) or not described to any of these (none) (3 experiments). F Cell cycle analysis of HSCs from control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice. Mean percentages of cells in G0, G1 and S/G2/M are shown (6–8 mice per genotype, 3 experiments). G Single LMPPs were co-cultured on OP9 stroma. Frequency of colonies (left) and linage output (right) for control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice are shown. Colony distribution defined as in panel (E) (5 experiments). H Flow cytometry plots of B progenitor compartment in control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice. Numbers show mean percentages of total CD45⁺ cells. I Frequencies of B progenitors as percentage of CD45⁺ cells in control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice (7 experiments, n_males = 8; n_females = 13–20) (ProB not defined by cKIT expression). J Single CD24⁺ PreProBs were co-cultured on OP9 stroma. Frequency of colonies (left) and linage output (right) for control and KMT2A::AFF1^Vav-Cre+ postnatally induced mice are shown. Colony distribution as defined in panel E (3 experiments). Bars show means ± SD and each dot represents an individual mouse. **p ≤ 0.01; ***p ≤ 0.001; n.s. not significant.