Proximal promoter elements of the human zeta-globin gene confer embryonic-specific expression on a linked reporter gene in transgenic mice.
We have investigated the transcriptional regulation of the human embryonic zeta-globin gene promoter. First, we examined the effect that deletion of sequences 5' to zeta-globin's CCAAT box have on zeta-promoter activity in erythroid cell lines. Deletions of sequences between -116 and -556 (cap = 0) had little effect while further deletion to -84 reduced zeta-promoter activity by only 2-3-fold in both transiently and stably transfected erythroid cells. Constructs containing 67, 84 and 556 bp of zeta-globin 5' flanking region linked to a beta-galactosidase reporter gene (lacZ) and hypersensitive site -40 (HS-40) of the human alpha-globin gene cluster were then employed for the generation of transgenic mice. LacZ expression from all constructs, including a 67 bp zeta-globin promoter, was erythroid-specific and most active between 8.5 and 10.5 days post-fertilisation. By 16.5 days gestation, lacZ expression dropped 40-100-fold. These results suggest that embryonic-specific activation of the human zeta-globin promoter is conferred by a 67 bp zeta-promoter fragment containing only a CCAAT and TATA box.
Pondel
M D
MD
The Sir William Dunn School of Pathology, Chemical Pathology Unit, University of Oxford, UK.
Sharpe
J A
JA
Clark
S
S
Pearson
L
L
Wood
W G
WG
Proudfoot
N J
NJ
D000818:Animals; D002460:Cell Line; D004622:Embryo, Mammalian; D004912:Erythrocytes / Q000166:cytology; D005260:Female; D005333:Fetus; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D005914:Globins / Q000235:genetics*; D006801:Humans; D007763:Lac Operon; D008099:Liver / Q000196:embryology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic; D014162:Transfection
D005914:Globins