scholarly journals The suppressor of Hairy-wing protein regulates the tissue-specific expression of the Drosophila gypsy retrotransposon.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 215-228 ◽  
Author(s):  
P A Smith ◽  
V G Corces

Abstract The gypsy retrotransposon of Drosophila melanogaster causes mutations that show temporal and tissue-specific phenotypes. These mutant phenotypes can be reversed by mutations in su(Hw), a gene that also regulates the transcription of the gypsy element. Gypsy encodes a full-length 7.0-kb RNA that is expressed in the salivary gland precursors and fat body of the embryo, imaginal discs and fat body of larvae, and fat body and ovaries of adult females. The su(Hw)-binding region inserted upstream of the promoter of a lacZ reporter gene can induce beta-galactosidase expression in a subset of the embryonic and larval tissues where gypsy is normally transcribed. This expression is dependent on the presence of a functional su(Hw) product, suggesting that this protein is a positive activator of gypsy transcription. Flies transformed with a construct in which the 5' LTR and leader sequences of gypsy are fused to lacZ show beta-galactosidase expression in all tissues where gypsy is normally expressed, indicating that sequences other than the su(Hw)-binding site are required for proper spatial and temporal expression of gypsy. Mutations in the zinc fingers of su(Hw) affect its ability to bind DNA and to induce transcription of the lacZ reporter gene. Two other structural domains of su(Hw) also play an important role in transcriptional regulation of gypsy. Deletion of the amino-terminal acidic domain results in the loss of lacZ expression in larval fat body and adult ovaries, whereas mutations in the leucine zipper region result in an increase of lacZ expression in larval fat body and a decrease in adult ovaries. These effects might be the result of interactions of su(Hw) with activator and repressor proteins through the acidic and leucine zipper domains to produce the final pattern of tissue-specific expression of gypsy.

2014 ◽  
Vol 307 (3) ◽  
pp. F356-F368 ◽  
Author(s):  
Scott S. Williams ◽  
Patricia Cobo-Stark ◽  
Sachin Hajarnis ◽  
Karam Aboudehen ◽  
Xinli Shao ◽  
...  

Autosomal recessive polycystic kidney disease, an inherited disorder characterized by the formation of cysts in renal collecting ducts and biliary dysgenesis, is caused by mutations of the polycystic kidney and hepatic disease 1 ( PKHD1) gene. Expression of PKHD1 is tissue specific and developmentally regulated. Here, we show that a 2.0-kb genomic fragment containing the proximal promoter of mouse Pkhd1 directs tissue-specific expression of a lacZ reporter gene in transgenic mice. LacZ is expressed in renal collecting ducts beginning during embryonic development but is not expressed in extrarenal tissues. The Pkhd1 promoter contains a binding site for the transcription factor hepatocyte nuclear factor (HNF)-1β, which is required for activity in transfected cells. Mutation of the HNF-1β-binding site abolishes the expression of the lacZ reporter gene in renal collecting ducts. Transgenes containing the 2.0-kb promoter and 2.7 kb of additional genomic sequence extending downstream to the second exon are expressed in the kidney, intrahepatic bile ducts, and male reproductive tract. This pattern overlaps with the endogenous expression of Pkhd1 and coincides with sites of expression of HNF-1β. We conclude that the proximal 2.0-kb promoter is sufficient for tissue-specific expression of Pkhd1 in renal collecting ducts in vivo and that HNF-1β is required for Pkhd1 promoter activity in collecting ducts. Additional genomic sequences located from exons 1-2 or elsewhere in the gene locus are required for expression in extrarenal tissues.


1994 ◽  
Vol 42 (7) ◽  
pp. 953-956 ◽  
Author(s):  
B Lal ◽  
M A Cahan ◽  
P O Couraud ◽  
G W Goldstein ◽  
J Laterra

Cell transplantation is commonly used in studies of CNS development, tumor biology, and gene therapy. Fluorescent dyes and the E. coli lacZ reporter gene are used to identify transplanted cells in host tissues. The usefulness of these methods depends on host autofluorescence and beta-galactosidase (beta-Gal) activity. Our interest in the CNS vasculature led us to examine vascular autofluorescence and beta-Gal activity in postnatal and adult rat brains. Brains were perfusion-fixed (3.7% paraformaldehyde), cryoprotected, and cryostat-sectioned (12 microns). Autofluorescent vessel profiles were quantitated in sections using rhodamine filter sets and beta-Gal-positive vessels were quantitated under bright-field after incubation of sections with X-Gal chromogenic substrate for 1-18 hr at 37 degrees C. Multifocal vessel autofluorescence appeared in postnatal Day (PND) 18 Lewis rats (0.6 +/- 0.4 vessels/field) and increased tenfold in adults (6.8 +/- 0.3/field). The numbers of beta-Gal-positive vessels in PND 18 and adult sections incubated with X-Gal for 18 hr were 21.1 +/- 1.7 and 119 +/- 17, respectively. Host beta-Gal staining was similar to that produced by implanted endothelial cells expressing the bacterial lacZ reporter gene. Reducing incubation times in X-Gal to less than 4 hr eliminated endogenous staining and retained lacZ-specific staining. The presence of vascular autofluorescence and endogenous beta-Gal activity must be considered when either fluorescence- or lacZ-dependent cell markers are used in rat brain.


1995 ◽  
Vol 108 (12) ◽  
pp. 3677-3684 ◽  
Author(s):  
G. Zhou ◽  
S. Garofalo ◽  
K. Mukhopadhyay ◽  
V. Lefebvre ◽  
C.N. Smith ◽  
...  

Type II collagen is a major chondrocyte-specific component of the cartilage extracellular matrix and it represents a typical differentiation marker of mature chondrocytes. In order to delineate cis-acting elements of the mouse pro alpha 1(II) collagen gene that control chondrocyte-specific expression in intact mouse embryos, we generated transgenic mice harboring chimeric constructions in which varying lengths of the promoter and intron 1 sequences were linked to a beta-galactosidase reporter gene. A construction containing a 3,000 bp promoter and a 3,020 bp intron 1 fragment directed high levels of beta-galactosidase expression specifically to chondrocytes. Expression of the transgene coincided with the temporal expression of the endogenous gene at all stages of embryonic development. Successive deletions of intron 1 delineated a 182 bp fragment which targeted beta-galactosidase expression to chondrocytes with the same specificity as the larger intron 1 fragment. Transgenic mice harboring a 309 bp Col2a1 promoter lacking intron 1 tester sequences showed no beta-galactosidase expression in chondrocytes. Reduction of the 182 bp fragment to a 73 bp subfragment surrounding a decamer sequence previously reported to be involved in chondrocyte specificity, resulted in loss of transgene expression in chondrocytes. When the Col2a1 promoter was replaced with a minimal beta-globin promoter, the 182 bp intron 1 sequence was still able to target expression of the transgene to chondrocytes. We conclude that a 182 bp intron 1 DNA segment of the mouse Col2a1 gene contains the necessary information to confer high-level, temporally correct, chondrocyte expression on a reporter gene in intact mouse embryos and that Col2a1 promoter sequences are dispensable for chondrocyte expression.


1995 ◽  
Vol 268 (2) ◽  
pp. E213-E218 ◽  
Author(s):  
J. M. Gimble ◽  
X. Hua ◽  
F. Wanker ◽  
C. Morgan ◽  
C. Robinson ◽  
...  

Lipoprotein lipase, an enzyme of central importance to lipid metabolism, is most abundant in adipose tissues, cardiac and skeletal muscle, and portions of the brain. The current work examined the murine lipoprotein lipase promoter using transient transfection, gel-retention analyses, and transgenic mice. Maximum expression of the luciferase reporter gene in transfected cells was observed with -101 bp of the promoter. Nuclear extracts from tissues expressing lipoprotein lipase contained DNA binding proteins that recognize the CCAAT box (-64 bp) and an octamer motif (-46 bp); this combination of factors was absent in nonexpressing tissues. Transgenic mice from three of five founders prepared with -1,824-bp promoter constructs expressed the luciferase reporter gene at highest levels in brown adipose tissue and brain. These findings suggest that the -1,824-bp promoter region contains sequence elements responsible for the tissue-specific transcription of lipoprotein lipase in vivo.


Author(s):  
Manfred Suckow ◽  
Martina Kutzner ◽  
Carsten Amuel ◽  
Cornelis P. Hollenberg ◽  
Gerd Gellissen

1994 ◽  
Vol 14 (6) ◽  
pp. 4002-4010
Author(s):  
H G Patterton ◽  
R T Simpson

It has been proposed that yeast MATa cell-specific genes are repressed in MAT alpha cells by the Mat alpha 2p repressor-directed placement of a nucleosome in a position that incorporates the TATA box of the MATa-specific gene close to the nucleosomal pseudodyad. In this study, we address this proposal directly with a series of plasmids designed to place the MATa-specific STE6 TATA box at different locations in a nucleosome and in the internucleosomal linker. These plasmids contain different lengths of synthetic random DNA between the Mat alpha 2p operator and the TATA box of the STE6 promoter, which is located upstream of a lacZ reporter gene in a multicopy plasmid. We show that in MAT alpha cells, a nucleosome is retained in an identical translational frame relative to the Mat alpha 2p operator in all the constructs investigated, irrespective of the sequence of the DNA wrapped onto the histone octamer. This result shows that the nucleosomal organization of the STE6 promoter in MAT alpha cells is not conferred by the sequence of the promoter itself. No expression of the lacZ reporter gene was detectable in MAT alpha cells in any of the constructs, even with the TATA box located in a short internucleosomal linker. These data indicate that repression of MATa-specific genes in MAT alpha cells does not require the precise translational placement of the TATA box close to the nucleosomal pseudodyad; the gene remains repressed when the TATA box is located within the investigated 250-bp region in the organized chromatin domain abutting the Mat alpha 2p operator in MAT alpha cells and may remain repressed with the TATA box located anywhere within this organized repression domain.


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