Non-erythroid Genes Inserted on Either Side of Human HS-40 Impair the Activation of Its Natural α-Globin Gene Targets without Being Themselves Preferentially Activated

Espéret, Corinne; Sabatier, Sandrine; Deville, Marie‐Alice; Ouazana, Roland; Bouhassira, Eric E.; Godet, Jacqueline; Morlé, François; Bernet, Agnès

doi:10.1074/jbc.m001757200

Cited by 13 publications

(22 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[19][20][21][22] This effect occurs when a neomycin gene is in either orientation with respect to the globin genes. 21 To analyze the phenotype of mHS Ϫ26 Ϫ/Ϫ without the interference from the neomycin gene, we crossbred floxed HS Ϫ26 ϩ/Ϫ mice with mice expressing Cre recombinase very early in development. Using Southern blot analysis, we identified mice in which the neomycin gene was deleted, leaving a single loxP site in the position originally containing HS Ϫ26 (Figure 1).…”

Section: Removal Of the Floxed Neomycin Gene Partly Restores ␣-Globinmentioning

confidence: 99%

Deletion of the mouse α-globin regulatory element (HS −26) has an unexpectedly mild phenotype

Anguita

Sharpe

Sloane-Stanley

et al. 2002

Blood

View full text Add to dashboard Cite

Natural deletions of the region upstream of the human ␣-globin gene cluster, together with expression studies in cell lines and transgenic mice, identified a single element (HS ؊40) as necessary and perhaps sufficient for high-level expression of the ␣-globin genes. A similar element occupies the corresponding position upstream of the mouse (m) ␣-globin genes (mHS ؊26) and was thought to have similar functional properties. We knocked out mHS ؊26 by homologous recombination and observed the surprising result that instead of the expected severe ␣-thalassemia phenotype, the mice had a mild disease. Transcription levels of the mouse genes were reduced by about 50%, but homozygotes were healthy, with normal hemoglobin levels and only mild decreases in mean corpuscular volume and mean corpuscular hemoglobin. These results may indicate differences in the regulation of the ␣-globin clusters in mice and humans or that additional cis-acting elements remain to be characterized in one or both clusters. (Blood. 2002;100:3450-3456)

show abstract

Section: Removal Of the Floxed Neomycin Gene Partly Restores ␣-Globinmentioning

confidence: 99%

Deletion of the mouse α-globin regulatory element (HS −26) has an unexpectedly mild phenotype

Anguita

Sharpe

Sloane-Stanley

et al. 2002

Blood

View full text Add to dashboard Cite

show abstract

“…Expression of all genes at all developmental stages is reduced slightly, and no abnormal developmental expression is detected. As seen previously, the presence of the PGK-neo gene exacerbates the reduction in expression caused by the deletion itself.The presence of selectable markers in the LCR has been shown to decrease transcription of linked globin genes in both the ␣ and the ␤ loci 18,19,26,28 ; however, the mechanism by which this occurs remains unknown. Therefore, it was of interest to determine whether the interference was dependent on the orientation of the selectable marker within the locus.…”

mentioning

confidence: 99%

Targeted deletion of 5′HS1 and 5′HS4 of the β-globin locus control region reveals additive activity of the DNaseI hypersensitive sites

Bender

Roach

Halow

et al. 2001

Blood

Self Cite

View full text Add to dashboard Cite

The mammalian ␤-globin locus is a multigenic, developmentally regulated, tissuespecific locus from which gene expression is regulated by a distal regulatory region, the locus control region (LCR). The functional mechanism by which the ␤-globin LCR stimulates transcription of the linked ␤-like globin genes remains unknown. The LCR is composed of a series of 5 DNaseI hypersensitive sites (5HSs) that form in the nucleus of erythroid precursors. These HSs are conserved among mammals, bind transcription factors that also bind to other parts of the locus, and compose the functional components of the LCR. To test the hypothesis that individual HSs have unique properties, homologous recombination was used to construct 5 lines of mice with individual deletions of each of the 5HSs of the endogenous murine ␤-globin LCR. Here it is reported that deletion of 5HS1 reduces expression of the linked genes by up to 24%, while deletion of 5HS4 leads to reductions of up to 27%. These deletions do not perturb the normal stagespecific expression of genes from this multigenic locus. In conjunction with previous studies of deletions of the other HSs and studies of deletion of the entire LCR, it is concluded that (1) none of the 5HSs is essential for nearly normal expression; (2) none of the HSs is required for proper developmental expression; and (3) the HSs do not appear to synergize either structurally or functionally, but rather form independently and appear to contribute additively to the overall expression from the locus. IntroductionThe multigene ␤-globin locus has been intensively studied as a model for the tissue-specific and developmental regulation of gene expression. 1 Transcription of the locus is restricted to erythroid cells, and each gene is expressed during specific developmental stages. Analysis of naturally occurring deletions in the human locus revealed that regions far upstream of the ␤-like globin genes are important for regulation of the locus. 2-4 These regions encompass major DNase I hypersensitive sites (5ЈHS1 to 5 in human, 5ЈHS1 to 6 in mouse) located upstream of the embryonic globin genes. [5][6][7][8][9] The smallest and most well studied of these deletions, the Hispanic thalassemia deletion, 4 removes 5ЈHS2 to 5 as well as 27 kilobases (kb) upstream of this region and leads to an alteration of the generalized DNase I sensitivity of the locus, alterations in the timing of replication and origin used, and the transcriptional silencing of the locus. 10 Linkage of large restriction fragments containing these 5ЈHSs to human ␤-globin genes leads to high-level expression in transgenic mice (reviewed in Grosveld et al 11 and Townes and Behringer 12 ) and contrasts with earlier studies in which isolated globin transgenes were expressed at low levels or not at all. 13 This region, the locus control region (LCR), is defined by its ability to mediate high-level, erythroidspecific expression of linked transgenes and to significantly reduce the influence of integration site on the expression of linked genes. Extensive ...

show abstract

“…This situation, however, rarely occurs naturally. There are situations in mammals in which TI has been demonstrated without overlapping transcription, such as the ␤-globin (15,16,20), ␣-globin (11,22), and granzyme (26) loci. Each of these loci contains multiple nonoverlapping genes, the expression of which is influenced by shared regulatory ele-ments, and in this situation, expression of one gene influences the expression of other genes at the locus.…”

mentioning

confidence: 99%

Transcriptional Interference by Independently Regulated Genes Occurs in Any Relative Arrangement of the Genes and Is Influenced by Chromosomal Integration Position

Eszterhas¹,

Bouhassira

Martin

et al. 2002

Molecular and Cellular Biology

Self Cite

156

148

View full text Add to dashboard Cite

Transcriptional interference is the influence, generally suppressive, of one active transcriptional unit on another unit linked in cis. Its wide occurrence in experimental systems suggests that it may also influence transcription in many loci, but little is known about its precise nature or underlying mechanisms. Here we report a study of the interaction of two nearly identical transcription units juxtaposed in various arrangements. Each reporter gene in the constructs has its own promoter and enhancer and a strong polyadenylation signal. We used recombinase-mediated cassette exchange (RMCE) to insert the constructs into previously tagged genomic sites in cultured cells. This strategy also allows the constructs to be assessed in both orientations with respect to flanking chromatin. In each of the possible arrangements (tandem, divergent, and convergent), the presence of two genes strongly suppresses expression of both genes compared to that of an identical single gene at the same integration site. The suppression is most severe with the convergent arrangement and least severe in total with the divergent arrangement, while the tandem arrangement is most strongly influenced by the integration site and the genes' orientation within the site. These results suggest that transcriptional interference could underlie some position effects and contribute to the regulation of genes in complex loci.

show abstract

Non-erythroid Genes Inserted on Either Side of Human HS-40 Impair the Activation of Its Natural α-Globin Gene Targets without Being Themselves Preferentially Activated

Cited by 13 publications

References 42 publications

Deletion of the mouse α-globin regulatory element (HS −26) has an unexpectedly mild phenotype

Deletion of the mouse α-globin regulatory element (HS −26) has an unexpectedly mild phenotype

Targeted deletion of 5′HS1 and 5′HS4 of the β-globin locus control region reveals additive activity of the DNaseI hypersensitive sites

Transcriptional Interference by Independently Regulated Genes Occurs in Any Relative Arrangement of the Genes and Is Influenced by Chromosomal Integration Position

Contact Info

Product

Resources

About