Maea maintains the postnatal EI. (A) Experimental design to determine the requirement of Maea during adult erythropoiesis using Maea^Mx1-Cre mice. (B) Quantification of total BMNCs, macrophages, and EBs in Maea^fl/fl and Maea^Mx1-Cre mice 3 weeks after the first Poly I:C injection (n = 7; data pooled from 2 independent experiments). (C) Validation of the specificity of mAb produced by hybridoma clone 92.25 by FACS staining of BM macrophages from wild-type control and Maea^Csf1r-Cre mice. (D-G) Quantification of total BM cellularity (D), BM EB numbers (E), EB maturation profile (F), and BM macrophage numbers (G) in isotype or anti-MAEA mAb-treated mice (n = 5). (H) Representative immunofluorescence images and quantification of erythroid cells per EI reconstituted in the presence of 10 μg/mL isotype or anti-MAEA mAb. Data are shown as mean plus or minus SEM. *P < .05, **P < .01, ****P < .0001 by unpaired Student t test. WBM, whole bone marrow.