Thomas W. Brotherton

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Pure populations of large, nucleated erythrocytes derived from yolk sac blood islands were obtained during normal fetal mouse development. Embryonic hemoglobins were present in these cells early in gestation. Later in gestation, an increasing amount of adults hemoglobin was also synthesized and accumulated in this population of primitive nucleated(More)
Mutant Ts/+ fetuses are developmentally retarded as compared to normal +/+ littermates. Mutant fetuses have less total hemoglobin than do normal fetuses of the same gestational age. However, when compared to +/+ fetuses of similar body weight, Ts/+ fetuses have the appropriate amount of total hemoglobin, suggesting that the apparent anemia observed in(More)
The relationship between the postsynthetic modification of core histones by methylation and transcriptionally active chromatin was investigated in K562 erythroleukemia cells. Cells were incubated with L-[methyl-3H]methionine in the presence of cycloheximide. Under these conditions, only histones H3 and H4 were detectably methylated. Chromatin was(More)
It has been previously shown that heparin can bind to chromatin and enhance transcriptional activity. To characterize this phenomenon further, we have studied the interaction of heparin with isolated core mononucleosomes from avian reticulocytes. The results of these studies suggest that heparin bound reversibly to intact core mononucleosomes to induce a(More)
We have studied histone acetylation in chicken erythrocytes. We find that about 30% of the histone in these cells is acetylated, however the majority of these histones are not in a dynamic steady state typical of other chicken cells and of mammalian cells, but rather are frozen in this state of modification. A very small fraction of erythrocyte histones are(More)
Using published methods for the isolation of nuclear proteins tightly bound to DNA, and resistant to removal by SDS or 16-BAC detergent and urea, several new protein bands in the region of 55 kd and 62 kd on SDS gel and 43 kd and 70 kd on 16--BAC gel electrophoresis were identified in extracts of avian erythroid nuclei. These bands were radiolabelled by(More)