Differential regulation of the rat phosphoenolpyruvate carboxykinase gene expression in several tissues of transgenic mice

1992 ◽  
Vol 12 (3) ◽  
pp. 1396-1403
Author(s):  
C L Eisenberger ◽  
H Nechushtan ◽  
H Cohen ◽  
M Shani ◽  
L Reshef

The selective expression of a unique copy gene in several mammalian tissues has been approached by studying the regulatory sequences needed to control expression of the rat phosphoenolpyruvate carboxykinase (PEPCK) gene in transgenic mice. A transgene containing the entire PEPCK gene, including 2.2 kb of the 5'-flanking region and 0.5 kb of the 3'-flanking region, exhibits tissue-specific expression in the liver, kidney, and adipose tissue, as well as the hormonal and developmental regulation inherent to endogenous gene expression. Deletions of the 5'-flanking region of the gene have shown the need for sequences downstream of position -540 of the PEPCK gene for expression in the liver and sequences downstream of position -362 for expression in the kidney. Additional sequences upstream of position -540 (up to -2200) are required for expression in adipose tissue. In addition, the region containing the glucocorticoid-responsive elements of the gene used by the kidney was identified. This same sequence was found to be needed specifically for developmental regulation of gene expression in the kidney and, together with upstream sequences, in the intestine. The apparently distinct sequence requirements in the various tissues indicate that the tissues use different mechanisms for expression of the same gene.

1992 ◽  
Vol 12 (3) ◽  
pp. 1396-1403 ◽  
Author(s):  
C L Eisenberger ◽  
H Nechushtan ◽  
H Cohen ◽  
M Shani ◽  
L Reshef

The selective expression of a unique copy gene in several mammalian tissues has been approached by studying the regulatory sequences needed to control expression of the rat phosphoenolpyruvate carboxykinase (PEPCK) gene in transgenic mice. A transgene containing the entire PEPCK gene, including 2.2 kb of the 5'-flanking region and 0.5 kb of the 3'-flanking region, exhibits tissue-specific expression in the liver, kidney, and adipose tissue, as well as the hormonal and developmental regulation inherent to endogenous gene expression. Deletions of the 5'-flanking region of the gene have shown the need for sequences downstream of position -540 of the PEPCK gene for expression in the liver and sequences downstream of position -362 for expression in the kidney. Additional sequences upstream of position -540 (up to -2200) are required for expression in adipose tissue. In addition, the region containing the glucocorticoid-responsive elements of the gene used by the kidney was identified. This same sequence was found to be needed specifically for developmental regulation of gene expression in the kidney and, together with upstream sequences, in the intestine. The apparently distinct sequence requirements in the various tissues indicate that the tissues use different mechanisms for expression of the same gene.


Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4602-4609 ◽  
Author(s):  
Susanna Porcu ◽  
Michael Kitamura ◽  
Ewa Witkowska ◽  
Zemin Zhang ◽  
Annick Mutero ◽  
...  

Abstract The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.


Blood ◽  
1997 ◽  
Vol 90 (11) ◽  
pp. 4602-4609 ◽  
Author(s):  
Susanna Porcu ◽  
Michael Kitamura ◽  
Ewa Witkowska ◽  
Zemin Zhang ◽  
Annick Mutero ◽  
...  

The human β globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult β globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the β globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from γ to β globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human β globin mRNA levels between lines. Human β globin mRNA levels were twofold to fourfold lower than that of mouse βmaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the β globin locus.


Endocrinology ◽  
2005 ◽  
Vol 146 (5) ◽  
pp. 2481-2488 ◽  
Author(s):  
Amrita Kamat ◽  
Margaret E. Smith ◽  
John M. Shelton ◽  
James A. Richardson ◽  
Carole R. Mendelson

Abstract The human aromatase (hCYP19) gene is controlled by tissue-specific promoters that lie upstream of tissue-specific first exons. Placenta-specific exon I.1 lies approximately 100,000 bp upstream of exon II. Previously, we observed that genomic sequences within 501 bp upstream of exon I.1 mediate placenta-specific expression. In the present study, transgenic mice were created carrying hCYP19I.1−246:hGH/hGX, hCYP19I.1−201:hGH, and hCYP19I.1−125:hGH fusion genes to further delineate 5′-flanking sequences within 501 bp of exon I.1 that are required to mediate placenta-specific hCYP19 gene expression. As little as 246 bp of hCYP19 exon I.1 5′-flanking sequence was sufficient to direct placenta-specific expression in transgenic mice. By contrast, transgenes containing 201 or 125 bp of exon I.1 5′-flanking DNA were not expressed in mouse placenta. Furthermore, hCYP19I.1−246:hGX transgene expression was developmentally regulated; expression was observed as early as embryonic d 7.5 (E7.5) in several cells of the trophoblast ectoderm, on E8.5 in some trophoblast giant cells, and by E9.5 in giant cells and the labyrinthine layer. By contrast, expression of the hCYP19I.1−501:hGH transgene was first observed on E10.5 and was restricted to the labyrinthine layer, which is most analogous to the human syncytiotrophoblast. This suggests the presence of regulatory elements between −501 and −246 bp that may bind inhibitory transcription factors expressed in giant cells. These findings from transgenic experiments together with deletion mapping studies using transfected human placental cells indicate that the concerted interaction of strong placenta-specific enhancers and silencers within this 501-bp region mediate labyrinthine and syncytiotrophoblast-specific CYP19 gene expression.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Herve Faralli ◽  
F. Jeffrey Dilworth

Expression of themyogenin(Myog) gene is restricted to skeletal muscle cells where the transcriptional activator turns on a gene expression program that permits the transition from proliferating myoblasts to differentiating myotubes. The strict temporal and spatial regulation onMyogexpression in the embryo makes it an ideal gene to study the developmental regulation of tissue-specific expression. Over the last 20 years, our knowledge of the regulation ofMyogexpression has evolved from the identification of the minimal promoter elements necessary for the gene to be transcribed in muscle, to a mechanistic understanding of how the proteins that bind these DNA elements work together to establish transcriptional competence. Here we present our current understanding of the developmental regulation of gene expression gained from studies of theMyoggene.


Blood ◽  
1995 ◽  
Vol 85 (2) ◽  
pp. 319-329 ◽  
Author(s):  
S Dziennis ◽  
RA Van Etten ◽  
HL Pahl ◽  
DL Morris ◽  
TL Rothstein ◽  
...  

Abstract CD11b is the alpha chain of the Mac-1 integrin and is preferentially expressed in myeloid cells (neutrophils, monocytes, and macrophages). We have previously shown that the CD11b promoter directs cell-type- specific expression in myeloid lines using transient transfection assays. To confirm that these promoter sequences contain the proper regulatory elements for correct myeloid expression of CD11b in vivo, we have used the -1.7-kb human CD11b promoter to direct reporter gene expression in transgenic mice. Stable founder lines were generated with two different reporter genes, a Thy 1.1 surface marker and the Escherichia coli lacZ (beta-galactosidase) gene. Analysis of founders generated with each reporter demonstrated that the CD11b promoter was capable of driving high levels of transgene expression in murine macrophages for the lifetime of the animals. Similar to the endogenous gene, transgene expression was preferentially found in mature monocytes, macrophages, and neutrophils and not in myeloid precursors. These experiments indicate that the -1.7 CD11b promoter contains the regulatory elements sufficient for high-level macrophage expression. This promoter should be useful for targeting heterologous gene expression to mature myeloid cells.


2005 ◽  
Vol 19 (9) ◽  
pp. 2320-2334 ◽  
Author(s):  
Amena Archer ◽  
Dominique Sauvaget ◽  
Valérie Chauffeton ◽  
Pierre-Etienne Bouchet ◽  
Jean Chambaz ◽  
...  

Abstract In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.


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