scholarly journals Genomic Regions that Mediate Placental Cell-Specific and Developmental Regulation of Human Cyp19 (Aromatase) Gene Expression in Transgenic Mice

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.

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.


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.


1987 ◽  
Vol 7 (10) ◽  
pp. 3749-3758
Author(s):  
V da C Soares ◽  
R M Gubits ◽  
P Feigelson ◽  
F Costantini

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene.


1999 ◽  
Vol 277 (4) ◽  
pp. F599-F610 ◽  
Author(s):  
Peter Igarashi ◽  
Cooduvalli S. Shashikant ◽  
R. Brent Thomson ◽  
Dilys A. Whyte ◽  
Shuxian Liu-Chen ◽  
...  

Kidney-specific cadherin (Ksp-cadherin, cadherin 16) is a tissue-specific member of the cadherin superfamily that is expressed exclusively in the basolateral membrane of tubular epithelial cells in the kidney. To determine the basis for tissue-specific expression of Ksp-cadherin in vivo, we evaluated the activity of the promoter in transgenic mice. Transgenic mice containing 3.3 kb of the mouse Ksp-cadherin promoter and an Escherichia coli lacZ reporter gene were generated by pronuclear microinjection. Assays of β-galactosidase enzyme activity showed that the transgene was expressed exclusively in the kidney in both adult and developing mice. Within the kidney, the transgene was expressed in a subset of renal tubular epithelial cells that endogenously expressed Ksp-cadherin and that were identified as collecting ducts by colabeling with Dolichos biflorus agglutinin. In the developing metanephros, expression of the transgene in the branching ureteric bud correlated with the developmental expression of Ksp-cadherin. Identical patterns of expression were observed in multiple founder mice, indicating that kidney specificity was independent of transgene integration site. However, heterocellular expression was observed consistent with repeat-induced gene silencing. We conclude that the Ksp-cadherin gene promoter directs kidney-specific expression in vivo. Regulatory elements that are sufficient to recapitulate the tissue- and differentiation-specific expression of Ksp-cadherin in the renal collecting duct are located within 3.3 kb upstream to the transcriptional start site.


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 ◽  
...  

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.


Author(s):  
Aravind Kumar Konda ◽  
Pallavi Singh ◽  
Khela Ram Soren ◽  
Narendra Pratap Singh

Promoters are cis-acting regulatory elements that are usually present upstream to the coding sequences and determine the gene expression. Deployment of tissue specific and inducible promoters are constantly increasing for development of successful and stable multiple transgenic plants. To this end, as a strategy for enhanced expression of cis or transgenes, promoter engineering of the native msg promoter from soya bean has been carried out for executing pod specific expression of genes. Cis regulatory elements such as 5’UTR and poly (A) tract have been incorporated for imparting mRNA stability and translational enhancement to generate the modified 1.285 Kb pod specific promoter. Further to attain transcriptional enhancement the modified promoter has been cloned to generate Bi-directional Duplex Promoters (BDDP). The engineered msg promoter gene constructs can be deployed for high level tissue specific gene expression of cis/trans genes along with chosen terminator in chickpea. soybean and other legumes as well.


1999 ◽  
Vol 276 (3) ◽  
pp. G666-G676 ◽  
Author(s):  
James R. Gum ◽  
James W. Hicks ◽  
Anne-Marie Gillespie ◽  
Elaine J. Carlson ◽  
Lazlo Kömüves ◽  
...  

The regulation of MUC2, a major goblet cell mucin gene, was examined by constructing transgenic mice containing bases −2864 to +17 of the human MUC25′-flanking region fused into the 5′-untranslated region of a human growth hormone (hGH) reporter gene. Four of eight transgenic lines expressed reporter. hGH message expression was highest in the distal small intestine, with only one line expressing comparable levels in the colon. This contrasts with endogenous MUC2 expression, which is expressed at its highest levels in the colon. Immunohistochemical analysis indicated that goblet cell-specific expression of reporter begins deep in the crypts, as does endogenous MUC2 gene expression. These results indicate that the MUC2 5′-flanking sequence contains elements sufficient for the appropriate expression of MUC2 in small intestinal goblet cells. Conversely, elements located outside this region appear necessary for efficient colonic expression, implying that the two tissues utilize different regulatory elements. Thus many, but not all, of the elements necessary for MUC2 gene regulation reside between bases −2864 and +17 of the 5′-flanking region.


1991 ◽  
Vol 11 (4) ◽  
pp. 2066-2074 ◽  
Author(s):  
J L Slack ◽  
D J Liska ◽  
P Bornstein

Studies in vitro have not adequately resolved the role of intronic and upstream elements in regulating expression of the alpha 1(I) collagen gene. To address this issue, we generated 12 separate lines of transgenic mice with alpha 1(I) collagen-human growth hormone (hGH) constructs containing different amounts of 5'-flanking sequence, with or without most of the first intron. Transgenes driven by 2.3 kb of alpha 1(I) 5'-flanking sequence, whether or not they contained the first intron, were expressed at a high level and in a tissue-specific manner in seven out of seven independent lines of transgenic mice. In most tissues, the transgene was expressed at levels approaching that of the endogenous alpha 1(I) gene and was regulated identically with the endogenous gene as animals aged. However, in lung, expression of the transgene was anomalously high, and in muscle, expression was lower than that of the endogenous gene, suggesting that in these tissues other regions of the gene may participate in directing appropriate expression. Five lines of mice were generated containing transgenes driven by 0.44 kb of alpha 1(I) 5'-flanking sequence (with or without the first intron), and expression was detected in four out of five of these lines. The level of expression of the 0.44-kb constructs in the major collagen-producing tissues was 15- to 500-fold lower than that observed with the longer 2.3-kb promoter. While transgenes containing the 0.44-kb promoter and the first intron retained a modest degree of tissue-specific expression, those without the first intron lacked tissue specificity and were poorly expressed in all tissues except lung.(ABSTRACT TRUNCATED AT 250 WORDS)


1987 ◽  
Vol 7 (10) ◽  
pp. 3749-3758 ◽  
Author(s):  
V da C Soares ◽  
R M Gubits ◽  
P Feigelson ◽  
F Costantini

To investigate the tissue-specific and hormonal regulation of the rat alpha 2u globulin gene family, we introduced one cloned member of the gene family into the mouse germ line and studied its expression in the resulting transgenic mice. Alpha 2u globulingene 207 was microinjected on a 7-kilobase DNA fragment, and four transgenic lines were analyzed. The transgene was expressed at very high levels, specifically in the liver and the preputial gland of adult male mice. The expression in male liver was first detected at puberty, and no expression was detected in female transgenic mice. This pattern of expression is similar to the expression of endogenous alpha 2u globulin genes in the rat but differs from the expression of the homologous mouse major urinary protein (MUP) gene family in that MUPs are synthesized in female liver and not in the male preputial gland. We conclude that these differences between rat alpha 2u globulin and mouse MUP gene expression are due to evolutionary differences in cis-acting regulatory elements. The expression of the alpha 2u globulin transgene in the liver was abolished by castration and fully restored after testosterone replacement. The expression could also be induced in the livers of female mice by treatment with either testosterone or dexamethasone, following ovariectomy and adrenalectomy. Therefore, the cis-acting elements responsible for regulation by these two hormones, as well as those responsible for tissue-specific expression, are closely linked to the alpha 2u globulin gene.


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