miR-144/451 deletion reduces mature erythroblasts in mouse FL. (A) The 25 most abundant miRNAs in WT erythroblasts, measured by miRNA-Seq. The miRNAs absent in KO erythroblasts are labeled red. Graph shows mean plus or minus standard error of the mean (SEM) for 3 biological replicates. The dotted red line marks 1% abundance. (B) Relative expression of miRNAs in WT vs KO erythroblasts. Each point represents a single miRNA plotted as percentage of total (average for 3 biological replicates). miRNAs absent in KO erythroblasts are circled and labeled in red. (C) Flow cytometry analysis of forward scatter and Ter119 expression in miR-144/451 WT and KO FL erythroblasts. (D) CD71 expression and forward scatter in the Ter119⁺ populations from panel C. Four progressive stages of erythroblast maturation (P2 to P5) are boxed. Bar graphs at right show mean plus or minus SEM for data from 10 biological replicates. *P < .05; ***P < .001. n.s., not significant by Mann-Whitney U test.