Structure and expression of a cloned beta o thalassaemic globin gene.
We have cloned the single beta-globin gene from an Italian patient who is a double heterozygote for beta o/delta beta o thalassaemia. RNA isolated from nucleated red cells from this patient can be translated in vitro to give detectable levels of A gamma- G gamma and alpha-globin, but no beta-globin. S1-mapping transcription studies show that beta-globin mRNA is present at about 1-3% of the level of alpha- and gamma-globin mRNA. In addition, the expression of this gene has been studied by reversed genetics. SV40-plasmid-beta o-globin gene recombinants have been transfected into Hela cells and analysed for beta-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 beta-globin mRNA is seen for the beta o thalassaemic globin gene and for a normal beta-globin gene. To elucidate the nature of the lesion, the entire DNA sequence of the beta-globin gene of this patient has been determined. The sequence shows that this gene contains a termination codon at position 39 (CAG - greater than UAG). Otherwise, there is a remarkable conservation of the entire DNA sequence.
D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D006801:Humans; D012333:RNA, Messenger / Q000032:analysis; D013539:Simian virus 40; D013789:Thalassemia / Q000235:genetics*
D012333:RNA, Messenger; D005914:Globins; D004247:DNA