Targeted inactivation of the major positive regulatory element (HS-40) of the human alpha-globin gene locus.
We have examined the role of the major positive upstream regulatory element of the human alpha-globin gene locus (HS-40) in its natural chromosomal context. Using homologous recombination, HS-40 was replaced by a neo marker gene in a mouse erythroleukemia hybrid cell line containing a single copy of human chromosome 16. In clones from which HS-40 had been deleted, human alpha-globin gene expression was severely reduced, although basal levels of alpha 1 and alpha 2-globin mRNA expression representing less than 3% of the level in control cell lines were detected. Deletion of the neo marker gene, by using FLP recombinase/FLP recombinase target system, proved that the phenotype observed was not caused by the regulatory elements of this marker gene. In the targeted clones, deletion of HS-40 apparently does not affect long-range or local chromatin structure at the alpha promoters. Therefore, these results indicate that, in the experimental system used, HS-40 behaves as a strong inducible enhancer of human alpha-globin gene expression.
Bernet
A
A
CNRS UMR 106, Université Claude Bernard Lyon, Villeurbanne, France.
Sabatier
S
S
Picketts
D J
DJ
Ouazana
R
R
Morlé
F
F
Higgs
D R
DR
Godet
J
J
D002460:Cell Line; D003850:Deoxyribonuclease I; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D016254:Mutagenesis, Insertional; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping
D012333:RNA, Messenger; D005914:Globins; D003850:Deoxyribonuclease I