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Differentiation of the MRNA Transcripts Originating from the Alpha 1- and Alpha 2-globin Loci in Normals and Alpha-thalassemics

Overview
Journal J Clin Invest
Specialty General Medicine
Date 1981 Aug 1
PMID 6894931
Citations 37
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Abstract

The alpha-globin polypeptide is encoded by two adjacent genes, alpha 1 and alpha 2. In the normal diploid state (alpha alpha/alpha alpha) all four alpha-globin genes are expressed. Loss or dysfunction of one or more of these genes leads to deficient alpha-globin production and results in alpha-thalassemia. We present a technique to differentially assess the steady-state levels of the alpha 1- and alpha-2-globin messenger RNA (mRNA) transcripts and thus delineate the relative level of expression of the two alpha-globin loci in a variety of alpha-thalassemia states. Only alpha 1 mRNA was produced in the alpha-thalassemia-2 haplotype (-alpha) (one of the two alpha-globin genes deleted from chromosome 16). This confirms previous gene mapping data which demonstrate deletion of the alpha 2 gene. The triple alpha-globin gene haplotype (alpha alpha alpha) is the reciprocal of the alpha-thalassemia-2 haplotype and thus contains an extra alpha 2-globin gene. RNA from this haplotype contained a greater than normal level of alpha 2-relative to alpha 1-globin mRNA. This data implies that the extra alpha 2 gene in the triple alpha-globin haplotype is functional. We detected a relative instability of the alpha 2-globin mRNA encoding the alpha-globin structural mutant Constant Spring. This instability may contribute to the low level of expression of the alpha-Constant Spring protein. In a Chinese patient with nondeletion hemoglobin-H disease (- -/alpha alpha T) (both alpha-globin genes are present but not fully functional) a normal ratio was maintained between the levels of alpha 1- and alpha 2-globin mRNA, implying that mRNA production from both alpha-globin genes is suppressed in a balanced manner. These observations extended previous findings concerning the structural rearrangements in the deletion types of alpha-thalassemia and the pathophysiology of two nondeletion variants.

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References
1.
Peacock A, DINGMAN C . Resolution of multiple ribonucleic acid species by polyacrylamide gel electrophoresis. Biochemistry. 1967; 6(6):1818-27. DOI: 10.1021/bi00858a033. View

2.
Orkin S, Goff S . The duplicated human alpha-globin genes: their relative expression as measured by RNA analysis. Cell. 1981; 24(2):345-51. DOI: 10.1016/0092-8674(81)90324-x. View

3.
Clegg J, Weatherall D, Milner P . Haemoglobin Constant Spring--a chain termination mutant?. Nature. 1971; 234(5328):337-40. DOI: 10.1038/234337a0. View

4.
Katz L, Kingsbury D, Helinski D . Stimulation by cyclic adenosine monophosphate of plasmid deoxyribonucleic acid replication and catabolite repression of the plasmid deoxyribonucleic acid-protein relaxation complex. J Bacteriol. 1973; 114(2):577-91. PMC: 251812. DOI: 10.1128/jb.114.2.577-591.1973. View

5.
Schimke R, Palacios R, Sullivan D, Kiely M, Gonzales C, Taylor J . Immunoadsorption of ovalbumin synthesizing polysosmes and partial purification of ovalbumin messenger RNA. Methods Enzymol. 1974; 30:631-48. DOI: 10.1016/0076-6879(74)30061-4. View