TY - JOUR
T1 - A characterization of globin mRNA sequences in the nucleus of duck immature red blood cells
AU - Strair, Roger K.
AU - Skoultchi, Arthur I.
AU - Shafritz, David A.
PY - 1977/9
Y1 - 1977/9
N2 - Studies were performed with duck immature red blood cells to identify and characterize the globin mRNA sequences in nuclear RNA. Annealing of 3H-globin cDNA to unlabeled nuclear RNA has identified three distinct size classes of nuclear RNA molecules containing globin mRNA sequences. The largest size class contained 1-2% of total nuclear globin mRNA sequences and sedimented through 85% formamide-sucrose gradients at the same rate as 28S ribosomal RNA. Chromatography on oligo(dT)-cellulose indicated that most of these molecules are not polyadenylated. The bulk of nuclear globin mRNA sequences (70%) was contained in polyadenylated RNA molecules which sedimented at 16.5S. The remainder of nuclear globin mRNA sequences (∼30%) was detected in molecules sedimenting at 10S (the position of cytoplasmic globin mRNA). To determine whether a precursor-product relationship exists between these nuclear molecules and cytoplasmic globin mRNA, pulse-label and chase experiments were performed. Labeled globin mRNA sequences were assayed by annealing to globin cDNA-cellulose. Labeled 28S nuclear globin RNA sequences could not be detected, perhaps due to technical reasons. 16.5S nuclear globin RNA was labeled and chased into cytoplasmic globin mRNA sequences. The half-life of 16.5S nuclear globin RNA was estimated to be less than 30 min. These results demonstrate that in duck immature red blood cells, globin mRNA is transcribed as a larger precursor. Furthermore, size characterization of this precursor during pulse-label and chase periods suggests that it is processed within the nucleus to 10S globin RNA.
AB - Studies were performed with duck immature red blood cells to identify and characterize the globin mRNA sequences in nuclear RNA. Annealing of 3H-globin cDNA to unlabeled nuclear RNA has identified three distinct size classes of nuclear RNA molecules containing globin mRNA sequences. The largest size class contained 1-2% of total nuclear globin mRNA sequences and sedimented through 85% formamide-sucrose gradients at the same rate as 28S ribosomal RNA. Chromatography on oligo(dT)-cellulose indicated that most of these molecules are not polyadenylated. The bulk of nuclear globin mRNA sequences (70%) was contained in polyadenylated RNA molecules which sedimented at 16.5S. The remainder of nuclear globin mRNA sequences (∼30%) was detected in molecules sedimenting at 10S (the position of cytoplasmic globin mRNA). To determine whether a precursor-product relationship exists between these nuclear molecules and cytoplasmic globin mRNA, pulse-label and chase experiments were performed. Labeled globin mRNA sequences were assayed by annealing to globin cDNA-cellulose. Labeled 28S nuclear globin RNA sequences could not be detected, perhaps due to technical reasons. 16.5S nuclear globin RNA was labeled and chased into cytoplasmic globin mRNA sequences. The half-life of 16.5S nuclear globin RNA was estimated to be less than 30 min. These results demonstrate that in duck immature red blood cells, globin mRNA is transcribed as a larger precursor. Furthermore, size characterization of this precursor during pulse-label and chase periods suggests that it is processed within the nucleus to 10S globin RNA.
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U2 - 10.1016/0092-8674(77)90191-X
DO - 10.1016/0092-8674(77)90191-X
M3 - Article
C2 - 561662
AN - SCOPUS:0017689743
SN - 0092-8674
VL - 12
SP - 133
EP - 141
JO - Cell
JF - Cell
IS - 1
ER -