Globin synthesis in erythroid bursts that mature sequentially in culture.
I. Studies in cultures of adult peripheral blood BFU-Es
T Papayannopoulou, B Nakamoto, S Kurachi and G Stamatoyannopoulos
To study whether the culture time at which the burst populations mature
influences the expression of fetal hemoglobin in bursts, we measured
hemoglobin synthesis in cohorts of fully hemoglobinized erythroid bursts
maturing sequentially in cultures of adult peripheral blood BFU- Es. 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 third culture week showed lower levels of fetal Hb synthesis compared
to bursts that are already mature in the second culture week. The decline
of gamma/gamma + beta ratio with culture time was also noted in erythroid
bursts composed of immature erythroblasts. The enhanced HbF formation in
peripheral blood BFU-E cultures is thus 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 that possess an active HbF program. The present data indicate
that the variation of HbF synthesis with culture time should be taken into
consideration when the influence of various culture conditions of HbF
synthesis is studied in BFU-E cultures.
Volume 58,
Issue 5,
pp. 969-974,
11/01/1981
Copyright © 1981 by The American Society of Hematology
