A deletion of the human β-globin locus activation region causes a major alteration in chromatin structure and replication across the entire β-globin locus

William C. Forrester, Elliot Epner, M. Catherine Driscoll, Tariq Enver, Martha Brice, Thalia Papayannopoulou, Mark Groudine

Research output: Contribution to journalArticle

372 Scopus citations


Naturally occurring deletions that remove sequences located ∼60 kb upstream of the human adult β-globin gene result in the failure to transcriptionally activate the cis-linked globin genes in erythroid cells. In addition, transfection, transgenic, and somatic cell hybrid studies have revealed that sequences within this region are essential for the developmentally regulated high-level expression of cis-linked globin genes. This regulatory region located at the 5′ end of the β-globin locus has been termed the locus activation region (LAR). Using somatic cell hybrids, we have studied the chromatin structure and timing of DNA replication of the normal human β-globin locus and a locus containing a de novo 25-kb deletion that removes elements of the LAR. As a result of this deletion, the entire β-globin locus and sequences ∼100 kb 5′ and 3′ of the adult β-globin gene are DNase I-resistant and do not form characteristic distant hypersensitive sites. These sequences also replicate late in S phase in an erythroid cell background. In contrast, the sequences of the normal locus are DNase I sensitive and early replicating. These results suggest that the LAR is required for both the erythroid-specific chromatin structure and timing of DNA replication over a large physical distance.

Original languageEnglish (US)
Pages (from-to)1637-1649
Number of pages13
JournalGenes and Development
Issue number10
Publication statusPublished - Jan 1 1990



  • Locus activation region
  • β-Globin gene

ASJC Scopus subject areas

  • Genetics
  • Developmental Biology

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