Impaired self-renewal of granulocyte-macrophage progenitors derived from GMPs of GATA-2^+/− marrow. LMPP, CMP, and GMP populations were sorted from each genotypic group and plated in colony-forming medium containing growth factors that were permissive for granulocyte-macrophage colony formation. After 10 days, CFC-GM colonies were enumerated and replated into fresh colony-forming medium. Secondary CFC-GM colonies were scored after 10 days in culture. The replating process was repeated an additional time to yield tertiary CFC-GM colonies. Three replicates were used per population per genotype in each experiment. The CFC-GM sequential replating potential of LMPP (A) (n = 4; P > .05), CMP (B) (n = 4; P > .05), and GMP (C) (n = 4; P < .05) from each genotype is depicted. ** indicates statistical significance. Error bars indicate SEM. Statistical analysis was performed using the paired Student t test.