scholarly journals Human alpha-globin genes demonstrate autonomous developmental regulation in transgenic mice.

1991 ◽  
Vol 11 (7) ◽  
pp. 3786-3794 ◽  
Author(s):  
M Albitar ◽  
M Katsumata ◽  
S A Liebhaber
Keyword(s):  
Transgenic Mice ◽  
Control Region ◽  
Globin Gene ◽  
Globin Genes ◽  
Beta Globin ◽  
Developmental Control ◽  
Beta Globin Gene ◽  
Human Adult ◽  
Alpha Globin ◽  
In Cis

Recent studies have demonstrated that transcriptional activation of the human adult beta-globin transgene in mice by coinsertion of the beta-globin cluster locus control region (beta-LCR) results in loss of its adult restricted pattern of expression. Normal developmental control is reestablished by coinsertion of the fetal gamma-globin transgene in cis to the adult beta-globin gene. To test the generality of this interdependence of two globin genes for their proper developmental control, we generated transgenic mice in which the human adult alpha-globin genes are transcriptionally activated by the beta-LCR either alone or in cis to their corresponding embryonic zeta-globin gene. In both cases, the human globin transgenes were expressed at the appropriate developmental period. In contrast to the beta-globin gene, developmental control of the human adult alpha-globin transgenes appears to be autonomous and maintained even when activated by an adjacent locus control region.

Human alpha-globin genes demonstrate autonomous developmental regulation in transgenic mice

1991 ◽  
Vol 11 (7) ◽  
pp. 3786-3794
Author(s):  
M Albitar ◽  
M Katsumata ◽  
S A Liebhaber
Keyword(s):  
Transgenic Mice ◽  
Control Region ◽  
Globin Gene ◽  
Globin Genes ◽  
Beta Globin ◽  
Developmental Control ◽  
Beta Globin Gene ◽  
Human Adult ◽  
Alpha Globin ◽  
In Cis

Recent studies have demonstrated that transcriptional activation of the human adult beta-globin transgene in mice by coinsertion of the beta-globin cluster locus control region (beta-LCR) results in loss of its adult restricted pattern of expression. Normal developmental control is reestablished by coinsertion of the fetal gamma-globin transgene in cis to the adult beta-globin gene. To test the generality of this interdependence of two globin genes for their proper developmental control, we generated transgenic mice in which the human adult alpha-globin genes are transcriptionally activated by the beta-LCR either alone or in cis to their corresponding embryonic zeta-globin gene. In both cases, the human globin transgenes were expressed at the appropriate developmental period. In contrast to the beta-globin gene, developmental control of the human adult alpha-globin transgenes appears to be autonomous and maintained even when activated by an adjacent locus control region.

Upstream G gamma-globin and downstream beta-globin sequences required for stage-specific expression in transgenic mice

1987 ◽  
Vol 7 (11) ◽  
pp. 4024-4029
Author(s):  
M Trudel ◽  
J Magram ◽  
L Bruckner ◽  
F Costantini
Keyword(s):  
Transgenic Mice ◽  
Fusion Gene ◽  
Globin Gene ◽  
Regulatory Elements ◽  
Globin Genes ◽  
Beta Globin ◽  
Erythroid Cells ◽  
Base Pairs ◽  
Beta Globin Gene ◽  
Gamma Globin

The human G gamma-globin and beta-globin genes are expressed in erythroid cells at different stages of human development, and previous studies have shown that the two cloned genes are also expressed in a differential stage-specific manner in transgenic mice. The G gamma-globin gene is expressed only in murine embryonic erythroid cells, while the beta-globin gene is active only at the fetal and adult stages. In this study, we analyzed transgenic mice carrying a series of hybrid genes in which different upstream, intragenic, or downstream sequences were contributed by the beta-globin or G gamma-globin gene. We found that hybrid 5'G gamma/3'beta globin genes containing G gamma-globin sequences upstream from the initiation codon were expressed in embryonic erythroid cells at levels similar to those of an intact G gamma-globin transgene. In contrast, beta-globin upstream sequences were insufficient for expression of 5'beta/3'G gamma hybrid globin genes or a beta-globin-metallothionein fusion gene in adult erythroid cells. However, beta-globin downstream sequences, including 212 base pairs of exon III and 1,900 base pairs of 3'-flanking DNA, were able to activate a 5'G gamma/3'beta hybrid globin gene in fetal and adult erythroid cells. These experiments suggest that positive regulatory elements upstream from the G gamma-globin and downstream from the beta-globin gene are involved in the differential expression of the two genes during development.

A silencer element from the alpha-globin gene inhibits expression of beta-like genes

1988 ◽  
Vol 8 (11) ◽  
pp. 5047-5051
Author(s):  
G F Atweh ◽  
J M Liu ◽  
H E Brickner ◽  
X X Zhu
Keyword(s):  
Globin Gene ◽  
Expression System ◽  
Globin Genes ◽  
Beta Globin ◽  
Base Pair Fragment ◽  
Alpha Globin ◽  
In Trans ◽  
Cis And Trans ◽  
In Cis ◽  
Silencer Element

We have studied the cis and trans interactions of the alpha- and beta-globin genes in a transient expression system. We found that the alpha-globin gene inhibited beta-globin expression in cis but not in trans. The silencer element responsible for this inhibition was localized to a 259-base-pair fragment at the 5' end of the alpha-globin gene.

scholarly journals Developmental switch in the relative expression of the alpha 1- and alpha 2-globin genes in humans and in transgenic mice

Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2471-2474 ◽  
Author(s):  
M Albitar ◽  
FE Cash ◽  
C Peschle ◽  
SA Liebhaber
Keyword(s):  
Transgenic Mice ◽  
Globin Gene ◽  
Gene Activation ◽  
Experimental System ◽  
Gene Clusters ◽  
Globin Genes ◽  
Beta Globin ◽  
Relative Expression ◽  
Structural Identity ◽  
Alpha Globin

Abstract Human alpha-globin is encoded by two adjacent genes, alpha 2 and alpha 1. Despite their remarkable level of structural identity, the more 5′ (alpha 2) gene is the major alpha-globin locus in the normal adult, expressed at 2.6-fold higher levels than the adjacent and more 3′ (alpha 1) globin gene. In light of the well-characterized pattern of gene activation in the human alpha- and beta-globin gene clusters during development, we considered the possibility that the relative expression of these two alpha-globin loci might be developmentally controlled. Analysis of human embryonic and early fetal erythroid RNA samples confirmed this possibility; levels of mRNA encoded by the two alpha-globin loci are equal in the embryo and subsequently shift to dominant expression of the alpha 2-globin locus at week 8 in utero. In transgenic mice carrying the entire human alpha-globin cluster (except for the theta gene) we show the same shift from equal expression of the alpha 1- and alpha 2-globin loci at the embryonic stage to predominance of the alpha 2-globin locus in the adult. These data demonstrate a switch in the expression of the two adjacent alpha-globin genes during the embryonic-to-fetal switch in erythroid development and provide an experimental system for its further characterization.

scholarly journals Developmental switch in the relative expression of the alpha 1- and alpha 2-globin genes in humans and in transgenic mice

Blood ◽  
1992 ◽  
Vol 79 (9) ◽  
pp. 2471-2474 ◽  
Author(s):  
M Albitar ◽  
FE Cash ◽  
C Peschle ◽  
SA Liebhaber
Keyword(s):  
Transgenic Mice ◽  
Globin Gene ◽  
Gene Activation ◽  
Experimental System ◽  
Gene Clusters ◽  
Globin Genes ◽  
Beta Globin ◽  
Relative Expression ◽  
Structural Identity ◽  
Alpha Globin

Human alpha-globin is encoded by two adjacent genes, alpha 2 and alpha 1. Despite their remarkable level of structural identity, the more 5′ (alpha 2) gene is the major alpha-globin locus in the normal adult, expressed at 2.6-fold higher levels than the adjacent and more 3′ (alpha 1) globin gene. In light of the well-characterized pattern of gene activation in the human alpha- and beta-globin gene clusters during development, we considered the possibility that the relative expression of these two alpha-globin loci might be developmentally controlled. Analysis of human embryonic and early fetal erythroid RNA samples confirmed this possibility; levels of mRNA encoded by the two alpha-globin loci are equal in the embryo and subsequently shift to dominant expression of the alpha 2-globin locus at week 8 in utero. In transgenic mice carrying the entire human alpha-globin cluster (except for the theta gene) we show the same shift from equal expression of the alpha 1- and alpha 2-globin loci at the embryonic stage to predominance of the alpha 2-globin locus in the adult. These data demonstrate a switch in the expression of the two adjacent alpha-globin genes during the embryonic-to-fetal switch in erythroid development and provide an experimental system for its further characterization.

scholarly journals A silencer element from the alpha-globin gene inhibits expression of beta-like genes.

1988 ◽  
Vol 8 (11) ◽  
pp. 5047-5051 ◽  
Author(s):  
G F Atweh ◽  
J M Liu ◽  
H E Brickner ◽  
X X Zhu
Keyword(s):  
Globin Gene ◽  
Expression System ◽  
Globin Genes ◽  
Beta Globin ◽  
Base Pair Fragment ◽  
Alpha Globin ◽  
In Trans ◽  
Cis And Trans ◽  
In Cis ◽  
Silencer Element

We have studied the cis and trans interactions of the alpha- and beta-globin genes in a transient expression system. We found that the alpha-globin gene inhibited beta-globin expression in cis but not in trans. The silencer element responsible for this inhibition was localized to a 259-base-pair fragment at the 5' end of the alpha-globin gene.

scholarly journals Human gamma- to beta-globin gene switching using a mini construct in transgenic mice.

1992 ◽  
Vol 12 (4) ◽  
pp. 1561-1567 ◽  
Author(s):  
J A Lloyd ◽  
J M Krakowsky ◽  
S C Crable ◽  
J B Lingrel
Keyword(s):  
Transgenic Mice ◽  
Developmental Regulation ◽  
Globin Gene ◽  
Globin Genes ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
High Level ◽  
Gene Switching ◽  
Globin Gene Expression

The developmental regulation of the human globin genes involves a key switch from fetal (gamma-) to adult (beta-) globin gene expression. It is possible to study the mechanism of this switch by expressing the human globin genes in transgenic mice. Previous work has shown that high-level expression of the human globin genes in transgenic mice requires the presence of the locus control region (LCR) upstream of the genes in the beta-globin locus. High-level, correct developmental regulation of beta-globin gene expression in transgenic mice has previously been accomplished only in 30- to 40-kb genomic constructs containing the LCR and multiple genes from the locus. This suggests that either competition for LCR sequences by other globin genes or the presence of intergenic sequences from the beta-globin locus is required to silence the beta-globin gene in embryonic life. The results presented here clearly show that the presence of the gamma-globin gene (3.3 kb) alone is sufficient to down-regulate the beta-globin gene in embryonic transgenic mice made with an LCR-gamma-beta-globin mini construct. The results also show that the gamma-globin gene is down-regulated in adult mice from most transgenic lines made with LCR-gamma-globin constructs not including the beta-globin gene, i.e., that the gamma-globin gene can be autonomously regulated. Evidence presented here suggests that a region 3' of the gamma-globin gene may be important for down-regulation in the adult. The 5'HS2 gamma en beta construct described is a suitable model for further study of the mechanism of human gamma- to beta-globin gene switching in transgenic mice.

Differential expression of alpha- and beta-globin genes in erythroleukemic cell lines

1990 ◽  
Vol 10 (7) ◽  
pp. 3591-3595
Author(s):  
N Beru ◽  
P B Maples ◽  
O Hermine ◽  
E Goldwasser
Keyword(s):  
Cell Lines ◽  
Globin Gene ◽  
Restriction Enzymes ◽  
Erythroid Differentiation ◽  
Globin Genes ◽  
Beta Globin ◽  
Globin Mrna ◽  
Beta Globin Gene ◽  
Alpha Globin ◽  
Erythroleukemic Cell

The IW32, NN10, and IW201 cell lines are erythroleukemic cell lines isolated from the spleens of mice infected with the Friend virus. IW32 and NN10 cells can be induced toward erythroid differentiation and hemoglobin synthesis by hemin or butyrate. Both cell lines contain some mature alpha- and beta-globin mRNA before induction, and addition of the inducers greatly increases the amount of globin message. Unlike IW32 and NN10 cells, IW201 cells are only partially inducible. Uninduced 201 cells contain a small amount of alpha-globin mRNA but no detectable beta-globin message. After induction, the cells contain markedly increased amounts of alpha-globin mRNA but still do not express the beta-globin gene. Southern blot analysis with 10 restriction enzymes shows that the restriction map of the beta-globin gene in IW201 cells is indistinguishable from that in IW32 and NN10 cells.

scholarly journals Regulated expression of the human beta globin gene in transgenic mice requires an upstream globin or nonglobin promoter.

1993 ◽  
Vol 4 (10) ◽  
pp. 1077-1085 ◽  
Author(s):  
K P Anderson ◽  
J A Lloyd ◽  
E Ponce ◽  
S C Crable ◽  
J C Neumann ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Globin Gene ◽  
Distance Effect ◽  
Developmental Expression ◽  
Gene Promoters ◽  
Globin Genes ◽  
Beta Globin ◽  
Beta Globin Gene ◽  
Gamma Globin ◽  
Erythroid Development

Transgenic mice have been used extensively to study elements governing the erythroid-specific developmental switch from human fetal gamma to human adult beta globin. Previous work demonstrated that a small construct composed of hypersensitive site 2 (HS2) of the locus control region (LCR) linked to the gamma and beta globin genes (HS2-gamma-beta) is sufficient for correct tissue and temporal expression of these genes, whereas HS2-beta alone is inappropriately expressed in the embryo. Two models, which are not mutually exclusive, have been proposed to explain these results and those of other constructs in transgenic mice. One model emphasizes the conserved polarity in the globin locus and suggests a distance effect whereby the beta globin gene must be removed from the LCR/HS2 to prevent an early and incorrect activation of this gene in the embryonic compartment. A second hypothesis proposes a competition between the gamma and beta globin gene promoters for interaction with the LCR/HS2. The active gamma globin gene promoter positioned between the LCR/HS2 and the beta globin gene thereby interacts with the HS2 elements early in erythroid development and is expressed until a change in putative stage-specific nuclear factors makes an interaction with the adult beta globin gene more favorable. In an effort to test the competition model, a construct has been prepared in which a small deletion was produced in the promoter region of the gamma globin gene while in the context of the HS2-gamma-beta plasmid. Analysis of this construct in transgenic mice reveals a constitutive unregulated expression of the human beta globin gene during erythroid development. To determine if this competition effect is specific for globin genes, a heterologous reporter gene has been substituted for the gamma globin gene in the construct HS2-gamma-beta. In this case, the beta globin gene exhibits correct developmental expression. This data is consistent with a model in which transcription from a promoter upstream of the beta globin gene in some manner protects this adult gene from activation by the LCR/HS2 during early development.

scholarly journals A single beta-globin locus control region element (5' hypersensitive site 2) is sufficient for developmental regulation of human globin genes in transgenic mice.

1992 ◽  
Vol 12 (5) ◽  
pp. 2057-2066 ◽  
Author(s):  
B J Morley ◽  
C A Abbott ◽  
J A Sharpe ◽  
J Lida ◽  
P S Chan-Thomas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Control Region ◽  
Developmental Regulation ◽  
Globin Gene ◽  
Locus Control Region ◽  
Erythroid Cell ◽  
Globin Genes ◽  
Beta Globin ◽  
Hypersensitive Site

The beta-globin gene complex is regulated by an upstream locus control region (LCR) which is responsible for high-level, position-independent, erythroid-cell-specific expression of the genes in the cluster. Its role in the developmental regulation of beta-like globin gene transcription remains to be established. We have examined the effect of a single LCR element, hypersensitive site 2 (HS2), on the developmental regulation of the human fetal gamma and adult beta genes in transgenic mice. In mice bearing HS2A gamma beta and HS2G gamma A gamma-117 delta beta human globin gene constructs, switching from gamma- to beta-gene expression begins at about day 13.5 of gestation and is largely completed shortly after birth. The larger construct also demonstrates a switch in G gamma- to A gamma-gene expression during the gamma-to-beta switch similar to that observed during normal human development. We conclude that HS2 alone is sufficient for developmental regulation of the human beta-globin genes.

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