Structure and expression of a cloned β°thalassaemic globin gene

• Published in: Nucleic acids research Vol. 9; no. 17; pp. 4391 - 4402
• Main Authors: Moschonas, N., de Boer, E., Grosveld, F.G., Dahl, H.H.M., Wright, S., Shewmaker, C.K., Flavell, R.A.
• Format: Journal Article
• Language: English
• Published: Oxford University Press 11.09.1981
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/9.17.4391

We have cloned the single β-globin gene from an Italian patient who is a double heterozygote for (β°/δβ° thalassaemia. RNA isolated from nucleated red cells from this patient can be translated in vitro to give detectable levels of Aγ- Gγ and α-globin, but no β-globin. S1-mapping transcription studies show that β-globin mRNA is present at about 1–3 % of the level of α- and γ-globin mRNA. In addition, the expression of this gene has been studied by reversed genetics. SV40-plasmid-β°-globin gene recombinants have been transfected into Hela cells and analysed for β-globin mRNA. In contrast to the results obtained with mRNA isolated directly from the blood of this patient, in the transfected Hela cells the same level of β-globin mRNA is seen for the β° thalassaemic globin gene and for a normal β-globin gene. To elucidate the nature of the lesion, the entire DNA sequence of the β-globin gene of this patient has been determined. The sequence shows that this gene contains a termination codon at position 39 (CAG → UAG). Otherwise, there is a remarkable conservation of the entire DNA sequence.