GLOBIN-SYNTHESIS IN ERYTHROID BURSTS THAT MATURE SEQUENTIALLY IN CULTURE .1. STUDIES IN CULTURES OF ADULT PERIPHERAL-BLOOD BFU-ES

  • 1 January 1981
    • journal article
    • research article
    • Vol. 58  (5) , 969-974
Abstract
To study whether the culture time at which the burst populations mature influences the expression of fetal Hb in bursts, Hb synthesis was measured in cohorts of fully hemoglobinized erythroid bursts maturing sequentially in cultures of adult peripheral blood BFU-E [erythropoietic burst forming cell]. In 13 of 15 experiments, a decline in .gamma./.gamma. + .beta. ratio was noted as the culture time advanced. On the average, erythroid bursts that mature during the 3rd culture wk showed lower levels of fetal Hb synthesis compared to bursts that are already mature in the 2nd culture wk. The decline of .gamma./.gamma. + .beta. ratio with culture time was noted in erythroid bursts composed of immature erythroblasts. The enhanced HbF formation in peripheral blood BFU-E cultures is most pronounced among the bursts that become hemoglobinized early, and there is a tendency for normalization of HbF synthesis in bursts that mature in late culture days. These results can be interpreted by several alternatives, including the possibility that the expression of high HbF levels in the early days of adult BFU-E cultures is a reflection of premature commitment to terminal differentiation of progenitors possessing an active HbF program. The variation of HbF synthesis with culture time apparently should be taken into consideration when the influence of various culture conditions on HbF synthesis is studied in BFU-E cultures.