期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：6
页码：3374-3379
DOI：10.1073/pnas.0634132100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The human {beta}-globin locus has been extensively studied as a model of tissue and developmental stage-specific gene expression. Structural mapping of naturally occurring mutations, including transfection and transgenic studies, and the recent finding of intergenic transcripts have suggested that there are cis-acting sequence elements in the A{gamma}-{delta} intergenic region involved in regulating {gamma}- and {beta}-globin gene expression. To determine whether previously identified sequences in the A{gamma}-{delta} intergenic region are required for appropriate developmental expression of the human {beta}-globin gene cluster, transgenic mice were generated by transfer of yeast artificial chromosomes containing the entire human {beta}-globin locus. Three different deletions of the A{gamma}-{delta} intergenic region were introduced, including (i) deletion of the 750-bp A{gamma} 3' regulatory element (A{gamma}e), (ii) deletion of 3.2 kb upstream of the {delta}-globin gene encompassing pyrimidine-rich sequences and the recently described intergenic transcript initiation site, and (iii) deletion of a 12.5-kb fragment encompassing most of the A{gamma}-{delta} globin intergenic region. Analysis of multiple transgenic lines carrying these deletion constructs demonstrated that the normal stage-specific sequential expression of the {varepsilon}-, {gamma}-, and {beta}-globin genes was preserved, despite deletion of these putative regulatory sequences. These studies suggest that regulatory sequences required for activation and silencing of the human {beta}-globin gene family during ontogeny reside proximally to the genes and immediately 5' to the human {gamma}- and {beta}-globin genes.
